Inductive charging including use of after-market accessories

ABSTRACT

A system and method for inductive charging including use of after-market accessories. In accordance with an embodiment, the system comprises a receiver coil or receiver associated with a mobile device, and provided as a separable or after-market accessory for use with the mobile device. When the mobile device is placed in proximity to a base unit having one or more charger coils, the charger coil is used to inductively generate a current in the receiver coil or receiver associated with the mobile device, to charge or power the mobile device. In accordance with various embodiments, the receiver can be a component of or attached to a shell, case, or other cover of the mobile device, provided as an after-market accessory that replaces an original shell, case, or cover, or connected to a power input jack of the mobile device and/or to battery connectors within the mobile device.

CLAIM OF PRIORITY AND CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/769,586, titled SYSTEM AND METHODS FOR INDUCTIVE CHARGING, ANDIMPROVEMENTS AND USES THEREOF”, filed Apr. 28, 2010; which applicationis a continuation-in-part of U.S. patent application Ser. No.12/116,876, titled “SYSTEM AND METHOD FOR INDUCTIVE CHARGING OF PORTABLEDEVICES”, filed May 7, 2008; which application claims the benefit ofpriority to U.S. Provisional Patent Applications Application No.61/173,497, titled “CONTEXTUALLY AWARE POWER AND COMMUNICATION FOR USEWITH MOBILE DEVICES”, filed Apr. 28, 2009; Application No. 61/178,807,titled “CONTEXTUALLY AWARE POWER AND COMMUNICATION FOR USE WITH MOBILEDEVICES”, filed May 15, 2009; Application No. 61/184,659, titled “SYSTEMAND METHOD FOR IMPROVED WIRELESS CHARGING AND POWER TRANSFER”, filedJun. 5, 2009; Application No. 61/223,673, titled “SYSTEM AND METHOD FORIMPROVED WIRELESS CHARGING AND POWER TRANSFER”, filed Jul. 7, 2009;Application No. 61/223,669, titled “SYSTEM AND METHOD FOR WIRELESSCHARGING OF DEVICES AND BATTERIES”, filed Jul. 7, 2009; Application No.61/304,320, titled “SYSTEM AND METHOD FOR PROVIDING WIRELESS POWERCHARGERS, RECEIVERS AND BATTERIES”, filed Feb. 12, 2010; and ApplicationNo. 61/317,946, titled “SYSTEMS AND METHODS FOR PROVIDING OR FOR USEWITH WIRELESS POWER CHARGERS, RECEIVERS AND BATTERIES”, filed Mar. 26,2010; which application is related to U.S. Patent ApplicationsApplication No. 60/763,816, titled “PORTABLE INDUCTIVE POWER SOURCE”,filed Jan. 31, 2006; Application No. 60/810,262, titled “MOBILE DEVICE,CHARGER, AND POWER SUPPLY”, filed Jun. 1, 2006; Application No.60/810,298, titled “MOBILE DEVICE, BATTERY, CHARGING SYSTEM, AND POWERSUPPLY SYSTEM”, filed Jun. 1, 2006; Application No. 60/868,674, titled“SYSTEM AND METHOD FOR PROVIDING AND USING A PORTABLE INDUCTIVE POWERSOURCE”, filed Dec. 5, 2006; application Ser. No. 11/669,113, titled“INDUCTIVE POWER SOURCE AND CHARGING SYSTEM”, filed Jan. 30, 2007;application Ser. No. 11/757,067, titled “POWER SOURCE, CHARGING SYSTEM,AND INDUCTIVE RECEIVER FOR MOBILE DEVICES”, filed Jun. 1, 2007;Application No. 60/916,748, titled “SYSTEM AND METHOD FOR CHARGING ANDPOWERING MOBILE DEVICES, BATTERIES, AND OTHER DEVICES”, filed May 8,2007; Application No. 60/952,835, titled “SYSTEM AND METHOD FORINDUCTIVE CHARGING OF PORTABLE DEVICES”, filed Jul. 30, 2007;Application No. 61/012,922, titled “WIRELESS CHARGER WITH POSITIONINSENSITIVITY TO PLACEMENT OF MOBILE DEVICES”, filed Dec. 12, 2007;Application No. 61/012,924, titled “SYSTEM AND METHOD FOR PROVIDINGCONTROL, REGULATION, AND COMMUNICATION IN CHARGERS AND POWER SUPPLIES”,filed Dec. 12, 2007; Application No. 61/015,606, titled “WIRELESSCHARGER WITH POSITION INSENSITIVITY TO PLACEMENT OF MOBILE ANDELECTRONIC DEVICES”, filed Dec. 20, 2007; and application Ser. No.12/116,876, titled “SYSTEM AND METHOD FOR INDUCTIVE CHARGING OF PORTABLEDEVICES”, filed May 7, 2008; each of which above applications are hereinincorporated by reference.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

FIELD OF INVENTION

The invention is related generally to power supplies and other powersources and chargers and particularly to inductive charging, and toimprovements, systems and methods for use thereof, such as improvedtransfer of wireless power to mobile devices and batteries.

BACKGROUND

With the increased use of mobile devices, many methods and protocols forwireless and wired connectivity and communication between nearby devices(several centimeters to meters) and also between devices and the widernetwork of farther devices (tens of meters to thousands of kilometers)are proliferating. For near devices, Bluetooth, WiFi, Wireless USB,Zigbee, Near Field Communication (NFC), HDMI, USB, Firewire, RS232,GPIB, etc., and other specialized device or application specificprotocols are common, while for larger distances devices may includewireless technologies such as 2G, 3G, 4G, GSM, Edge, WiMAX, EVDO,Satellite, Optical, or GPS etc. or wired technologies such as Ethernet,Dial up modem, DSL, Fiber, Power Line, etc. may coexist in a singledevice.

While these technologies provide huge advantages to users inconnectivity and communication, the vast majority of electronics have sofar been powered or charged through traditional use of wired powersupplies and chargers.

Recently, there has been an interest in providing a universal wirelessmethod for powering or charging one or several mobile devices,batteries, or electronics devices in general simultaneously. These“wireless power” methods can be generally divided into conductive andinductive methods. While the conductive methods use flow of current froma charger and/or power supply into the mobile devices to provide powerand therefore are not strictly speaking wireless, they offer geometrieswhere a user can place a device on a pad or similar object and receivepower through matching contacts on the back of a device and the padwithout ‘plugging in’ the device. The inductive methods (includingvariations such as magnetic resonance) utilize coils or wires in acharger and/or power supply to create a magnetic field in the vicinityof the surface. A coil or wire in a receiver embedded into or on adevice or battery that is in the vicinity of the surface can sense themagnetic field. Power from the charger and/or power supply can betransferred to the receiver without any wired connection through air orother media in between.

However despite advances in “wireless power”, both with the conductiveand inductive approaches, little progress has been made in terms ofincreasing efficiency, such as improved transfer of wireless power, andnew uses and applications for such systems. This is the general areathat embodiments of the invention are intended to address.

SUMMARY

Described herein are various systems and methods for use with powersupplies and other power sources and chargers and particularly thosethat use inductive charging, including systems and methods for usethereof, such as improved transfer of wireless power to mobile devicesand batteries.

In accordance with some embodiments described herein, various methodsare described by which the wired and/or wireless power devices andchargers or power supplies can provide additional connectivity andcommunications capabilities. In this way, in addition to charging,during the charging or docking process, other activities that are usefulto the user can be implemented.

In accordance with some embodiments described herein, features can beprovided that overcome several shortcomings of previous approaches,including methods by which the wireless power devices and chargers orpower supplies can provide better thermal performance, better detectionof external objects, and better power transfer efficiencies, and canenable operation at greater distance between charger and receiver coils.

In accordance with some embodiments described herein, a wireless chargersystem or system for transfer of power wirelessly can be provided inseveral different geometries and/or modes.

In accordance with some embodiments described herein, a device isdescribed by which the wireless charger and/or power supply is a devicethat is powered by a power source from another device such as the poweravailable from the USB or PCMCIA port or similar from a laptop computeror a peripheral hub or consumer electronic or communication device suchas a music player, TV, video player, stereo, or car stereo USB or otheroutlets which include power.

In accordance with some embodiments described herein, features can beprovided to improve charging efficiency, usage, and other features, andcan be used in combination with systems and methods described, forexample, in U.S. patent application Ser. No. 11/669,113, filed Jan. 30,2007 (published as U.S. Patent Publication No. 20070182367); U.S. patentapplication Ser. No. 11/757,067, filed Jun. 1, 2007 (published as U.S.Patent Publication No. 20070279002); and U.S. patent application Ser.No. 12/116,876, filed May 7, 2008, (published as U.S. Patent PublicationNo. 20090096413), each of which applications are incorporated byreference herein.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows an illustration of a circuit in accordance with anembodiment.

FIG. 2 shows an illustration of a circuit in accordance with anembodiment.

FIG. 3 shows an illustration of a circuit in accordance with anembodiment.

FIG. 4 shows an illustration of a circuit in accordance with anembodiment.

FIG. 5 shows an illustration of a wireless charger and/or power receiverintegrated into a mobile device battery cover or back cover inaccordance with an embodiment.

FIG. 6 shows an illustration of a receiver integrated into a mobiledevice and/or battery, in accordance with an embodiment.

FIG. 7 shows an illustration of an inductive charging system where thereceiver coil (top coil and its substrate) is integrated into or on arechargeable battery, or into or on a mobile, electronic, or electricdevice, in accordance with an embodiment.

FIG. 8 shows an illustration of a helical coil and a representativeshape for the generated magnetic flux by this coil, in accordance withan embodiment.

FIG. 9 shows an illustration of a coil designed to have an annular shapewith no winding in the middle, in accordance with an embodiment.

FIG. 10 shows an illustration of the integration of the wire wound orPCB or stand-alone coil on a metal layer surrounding the coil, inaccordance with an embodiment.

FIG. 11 shows an illustration of a metal layer cut at one or severalplaces to avoid the possibility of creation of circulating currents inthe metal surrounding the coil, in accordance with an embodiment.

FIG. 12 shows an illustration of an embodiment wherein a metal or otherthermally conductive layer is used for heat removal from the coil.

FIG. 13 shows an illustration of an embodiment including the use of heatdistribution away from the coil with a metal layer below the coil.

FIG. 14 shows an illustration of an embodiment which uses use heatdistribution away from the coil with a metal layer below the coil.

FIG. 15 illustrates the use of heat distribution away from the coil witha metal layer below the coil, in accordance with an embodiment.

FIG. 16 illustrates the use of heat distribution away from the coil witha metal layer below the coil, in accordance with an embodiment.

FIG. 17 illustrates the placement of a material between the substratefor the antenna coil (marked IC card, IC tag) for the NFC or RFID cardand a metal backing material such as a battery case or in case the RFIDis attached to a metallic material, in accordance with an embodiment.

FIG. 18 is an illustration of several geometries.

FIG. 19 illustrates a charger and receiver for inductive wireless powertransmission with magnetic layer shielding and annular magnet outside ofthe magnet shield layer area, in accordance with an embodiment.

FIG. 20 shows an illustration of a design for integration of a wirelesscharger and/or power receiver into a mobile device battery cover or backcover, in accordance with an embodiment.

FIG. 21 shows an illustration of another embodiment, in which theinductive coil and receiver is integrated into or on a battery.

FIG. 22 shows an illustration of another embodiment, in which thereceiver circuit is integrated in the inside or outside of the deviceback or battery door.

FIG. 23 illustrates an embodiment including a wireless inductive chargerand Inductive receiver coil and circuit.

FIG. 24 is an illustration of another embodiment for enabling chargingof cylindrical batteries.

FIG. 25 is an illustration of another embodiment , in which the chargercan include multiple coils for charging several batteries at the sametime

FIG. 26 is an illustration of another embodiment, including a wirelesscharger and/or power supply is in the form of a small device thatincludes a USB connector and directly connects to the side of a laptopto form a platform area where a phone, camera, or other mobile device orbattery can be placed and can receive power to operate and/or charge.

FIG. 27 illustrates an embodiment for mobile devices such as a mobilephone, MP3 or video player, game station, laptop, tablet computer, bookreader, Computer or video or TV display, etc, a wireless charger and/orpower supply is integrated into a stand or holder for such a mobiledevice so that the mobile device can be powered or charged when placedon the stand.

FIG. 28 illustrates a further embodiment of a charger/power stand whichcould in addition incorporate an area for charging/powering a keyboardand/or a mouse and/or joystick or remote control and/or other mobiledevices such as mobile phone, MP3 player, camera, game player, remotecontrol, battery.

FIG. 29 illustrates embodiments wherein a skin or case for a mobilephone includes a rechargeable battery and connector for the mobilephone.

FIG. 30 illustrates a removable or fixed receiver coil and electronicsthat can fit into a slot to allow the notebook computer to be wirelesslycharged from below the notebook computer, in accordance with anembodiment.

FIG. 31 illustrates a wireless charger and/or power supply, inaccordance with an embodiment.

FIG. 32 illustrates another embodiment where the wireless receiver coiland/or electronics are housed in a device attached to the bottom of anotebook computer through a connector that exists in many laptops fordocking.

FIG. 33 illustrates a configuration for the circuitry which can beincluded in common Li-Ion batteries.

FIG. 34 illustrates a battery that may contain specialized circuitry toprovide battery ID or authentication.

FIG. 35 illustrates a wireless charging receiver, in accordance with anembodiment.

FIG. 36 illustrates an implementation of a case or battery door for amobile device such as a mobile phone, in accordance with an embodiment.

FIG. 37 illustrates a receiver coil and circuit integrated into a mobilephone battery, in accordance with an embodiment.

FIG. 38 is an illustration of a wirelessly chargeable battery pack thatmay include one or more battery cells, battery protection and/or IDcircuit and/or temperature sensors such as thermistors, in accordancewith an embodiment.

FIG. 39 illustrates the flow of current (in dashed lines) when themobile device is plugged into an external wired charger and orcharger/data cable and another device such as a notebook or desktopcomputer, in accordance with an embodiment.

FIGS. 40 and 41 illustrate implementations of a wireless chargeablebattery for mobile devices, in accordance with an embodiment.

FIG. 42 illustrates a side view of the battery with various layers ofthe receiver coil, optional heat, electromagnetic shield and/or optionalalignment magnet or magnets shown, in accordance with an embodiment.

FIG. 43 is an illustration of a case where an alignment disk magnet isincorporated into the center of a coil in a manner not to increase theoverall thickness of the receiver coil/shield layer/magnet stack, inaccordance with an embodiment.

FIGS. 44 and 45 illustrate other implementations with annular or ring orarc alignment magnets whereby the magnet is on the outside of thereceiver coil and the coil and/or the electromagnetic/heat shield layerscan fit inside the ring or annular or arc magnets between the coil andthe battery cell, in accordance with an embodiment.

FIG. 46 illustrates an embodiment wherein a metal layer withdiscontinuous portions is placed behind and/or around the coil.

FIG. 47 is an illustration of an embodiment where the heat transferlayer is implemented on the same layer as the coil or is constructed notto overlap the coil structure.

DETAILED DESCRIPTION:

With the proliferation of mobile devices in recent years, the area ofpowering and charging these devices has attracted more attention. Thevast majority of the electronic devices in use today are powered and/orcharged through conduction of electricity through wires from a powersupply or charger to the device. While this method has proven to beefficient for most stationary devices, recently, there has been aninterest in providing wireless methods for powering or charging one orseveral mobile devices, batteries, or electronics devices. Theadvantages include the ability to eliminate a charger and/or powersupply cord and the possibility of implementing a universalcharger/power supply that can be able to charge/power multiple devicesone at a time or simultaneously. The so called “wireless power” methodscan also be generally divided into conductive and inductive methods.While the conductive methods use flow of current from a charger into themobile devices and/or battery to provide power and therefore are notstrictly speaking wireless, they offer geometries where a user can placea device on a pad or similar object and receive power through matchingcontacts on the back of a device or an after market cover or ‘skin’ andthe pad without ‘plugging in’ the device. Methods based on an array ofconnectors or strips of metal in a pad that can power mobile devicesconductively have been proposed.

The inductive methods utilize coils or wires near the surface of acharger and/or power supply to create a magnetic field in the vicinityof the surface. A coil or wire in a receiver embedded into a device thatis in the vicinity of the surface can sense the magnetic field. Powerfrom the charger can be transferred to the receiver without any wiredconnection through air or other media in between. By using a higherQuality Factor (Q) resonant circuit, the distance between a wirelesscharger and/or power supply and receiver coil has been where, ingeneral, larger distances are achieved at the expense of efficiencyincreased. These so called magnetic resonance techniques for wirelesspower transfer are a variation on the inductive power transfer and willbe considered in that category in the discussion here.

The inductive method has several advantages over the conductiveapproach, such as:

-   -   Connectors that are a major failure point in electronics are        eliminated.    -   Environmentally hermetic devices can be developed that are        immune to moisture or liquids.    -   The receiver can be built directly on the battery so the battery        can be charged through the outside shell of the device by        induction. This enables changing the battery of any existing        product after-market with a similar sized and shaped battery to        enable inductive charging.    -   With a properly designed charger and/or power supply pad, the        charging/powering is independent of position and does not        require placement of device in any particular location or        orientation.

As described herein, powering or charging of a mobile or electronicdevice or battery may be used interchangeably. Many mobile devicesincorporate rechargeable batteries and require external DC power tocharge these batteries for operation. However, in case of some devicessuch as a computer laptop, while the device is connected to DC power tocharge its internal battery, the device may also be using the DC powerto operate simultaneously. The ratio of power used for charging theinternal rechargeable battery to operating the device depends on thedegree to which the battery is discharged, the power necessary tooperate the device, and what the device is doing at any given time. Inthe extreme, a laptop with its battery removed may only use the DC powerto operate. In this case no charging occurs and 100% of the provided DCpower is used to operate the device.

Contextually Aware Inductive Charger/Receiver

In accordance with some embodiments described herein, various methodsare described by which the wired and/or wireless power devices andchargers or power supplies can provide additional connectivity andcommunications capabilities. In this way, in addition to charging,during the charging or docking process, other activities that are usefulto the user can be implemented. While most of the description below isbased on wired and/or the inductive method, the embodiments describedhere can be implemented with traditional wired charging and/or power andwireless charging and/or power through the inductive method or theconductive method or the magnetic resonance method, optical, or othermethods for power transfer some of which have been described above.Inductive methods of power transfer are described below as an example ofthe more general wireless power transfer.

With the proliferation of the wireless charging and/or power andcommunications technologies, many new embodiments of products andservices can be implemented that can provide user convenience.Especially, the combination of wireless power and wirelesscommunications technologies provides a seamless convenient userexperience that is very attractive in the mobile environment. In thisembodiment, several architectures and methods for combiningcharging/power transfer with data/signal communication to provideadditional functionality and use cases that are ‘contextually aware’ aredescribed. By contextually aware charging or power and communication, wemean that the mobile device or the charging platform adapts to thelocation or use model of interest to the user and environment andprovides different functionalities, applications and features dependingon preset or ad hoc conditions.

FIG. 1 is a high level view of a mobile device and/or battery incommunication with a host device that is also being powered and/orcharged. The host device may be a charging pad or docking station, orcan be a laptop, kiosk, car, train, airplane, computer, data gateway,set top box, game station, speakers, video monitor, music or videosystem, a piece of furniture such as a desk, chair, etc. The mobiledevice and/or the host can itself be connected to the Personal AreaNetwork (PAN), Local Area Network (LAN), Wide Area Network (WAN),Metropolitan Area Network (MAN), Satellite, or cellular networks (3G,4G, GSM, Edge, etc.) or specific navigation or other networks throughwired methods, wireless methods, fiber optics, DSL, WiMAX, WiFi, dial upmodem, etc. Also the host and the mobile device can communicate througha variety of wired or wireless methods such as USB, Bluetooth, WiFi,WiMAX, Wireless USB, etc. The means for the charging and/or powering ofthe mobile device and/or the host can be wired (through an AC/DCadaptor, USB or mini-usb connector, etc.) or wireless (throughinduction, conduction, magnetic resonance techniques, microwave,optical, solar cells, etc.). In the figure, only a subset of potentialprotocols and methods for connectivity and communication andcharging/power have been shown but the extension to other protocolsincluding specific protocols for control of devices in the home and/orcar or other specific situations is clear for the persons in the field.

In FIG. 1, as an example, the basic components of an inductive wirelesscharging system are shown. In accordance with an embodiment, the systemcomprises the power paths and power control signals shown in solidlines. Data lines are in dashed lines. Double dashed lines representconnections that can be data or charger and/or power supply signals. Thecharger and/or power supply comprises a drive circuit for exciting thecharger coil. This can be a field effect transistor (FET) or othertransistor for generating the alternating current to drive the coil. Theregulation/communication and control section is responsible forcontrolling the frequency/pulse duration, or other characteristics ofthe drive to control the transferred power or to communicate a signal ordata to the receiver. In addition, the circuit can contain a sensecircuit that is used to sense the proximity of the receiver and/or as acomponent for data or signal transfer between the charger and/or powersupply and the receiver. In the general geometry shown in FIG. 1, theregulation/communication and control portion or a separate circuit canalso provide a communication channel for data to and from a host devicesuch as a laptop or other mobile device or an environment such as a caror other vehicle or home or office computer or other device where thecharger/power supply is located or is connected to or nearby. By beingnear each other, we mean that 2 devices are within a distance such thatthey can interact through a wireless, wired, optical, or other method orprotocol within a Personal Area Network (PAN) or Local Area Network(LAN). The mobile device and/or the host can contain additionalcommunication systems such as Bluetooth, WiFi, WiMAX, Wireless USB,Zigbee, NFC, GPS, or wired communications such as USB, Ethernet, DSL,Modem, Fiber optics, Optical, HDMI, Power Line Communication (PLC), orother protocols for communications and control between devices andinternet or systems such as in the house, car, etc. The charging and/orpower for the mobile device may be through induction, conduction,resonant magnetic power transfer, optical power, etc. and/or traditionalwired technologies.

In the description provided herein, data is defined as information orfile or signals that are exchanged that are not necessarily directlyinvolved in the charging/power supply operation. Another example ofinformation being exchanged between components for charging/power supplyfunction is charger signal (CS). Examples of data can be name, address,phone number, or calendar information, music, video, TV, podcasts, orimage files or application files. In addition data can be informationrelated to amount of charge in a battery, presence of a mobile device ona charger, type of device being charged, information about the user ofthe mobile device and their preferences, location or status of themobile device, battery, charger or host, etc. In FIG. 1, the data lineshave been shown in dotted line while the solid lines representconnections for charging function. Some connections such as the one fromthe sense circuit to the regulation, communication and control can befor data or charging signal depending on whether any data exchange isimplemented or the sense circuit is strictly used for charger and/orpower supply signal functions. Similarly, for example, the connectionfrom the mobile device to the regulation, communication, and controlcircuit in the receiver can be either for data or charger and/or powersupply signal. These signals are shown with double dotted lines inFIG. 1. The breakdown between CS and data shown is as an example andmany other situations where the signals may be interpreted as belongingto either group may occur.

In FIG. 1, a general schematic which can include bi-directional data andCS transfer is shown. However, the flow of information can beuni-directional as well. In this case, for example, if the CS and datais from receiver to charger and/or power supply, only a sense circuit inthe charger and/or power supply may be implemented. In the block diagramshown in FIG. 1, the data from the charger and/or power supply to thereceiver can be transferred by low or high frequency modulation of theamplitude of the power signal (the drive signal for power transfer) orfrequency modulation and filtering or synching in the receiver. Thesetechniques are often used in communication circuits and can be appliedhere. Data or CS information can be transferred from receiver to chargerand/or power supply by techniques such as modulating the load impedanceof the receiver, or other techniques, as described for example in U.S.Patent Application titled “SYSTEM AND METHOD FOR INDUCTIVE CHARGING OFPORTABLE DEVICES”, application Ser. No. 12/116,876, filed May 7, 2008,(published as U.S. Patent Publication No. 20090096413), which isincorporated by reference herein. In this way, any data or CS in thereceiver appears as a change in the load of the charger and/or powersupply output and can be sensed by the charger and/or power supply sensecircuitry. The data exchanged between the charger and/or power supplyand the receiver can be exchanged in analog or digital format and manyoptions for this exchange exist.

In accordance with other embodiments, it is possible to have the dataand/or charge signal data transferred through another mechanism separatefrom the power signal. In the embodiment shown in FIG. 2, a wirelesschannel for data and CS is shown where the wireless channel can be adedicated special channel between the charger and/or power supply andthe receiver or can be based on an existing protocol such as Bluetooth,WiFi, WiMAX, Wireless USB, Zigbee, NFC, etc. or a custom or proprietaryprotocol.

FIG. 2 shows a wired and/or wireless charger and/or power supply andreceiver architecture with a separate wireless connection for dataand/or charger and/or power supply signal information. In accordancewith another embodiment, it is also possible for this channel to bethrough another set of coils.

FIG. 3 shows a wired and/or wireless charger and/or power supply andreceiver architecture with a separate inductive connection for dataand/or charger and/or power supply signal information in accordance withanother embodiment. In FIG. 3, the CS and/or data is communicatedthrough a second set of coils that may be separate from the powertransfer set of coils. The two sets of coils can be physically separateor be wound wires or PCB coils that are manufactured to be flat orcurved and be on the same plane or close to each other. The differentcoils for power and CS and/or data in FIG. 3 can be operated atdifferent frequencies to avoid interference or be at the same frequencybut physically separated to provide isolation.

FIG. 4 shows a wired and/or wireless charger and/or power supply andreceiver architecture with a separate optical transceiver oropto-coupler for data and/or charger and/or power signal information inaccordance with an embodiment. In FIG. 4, the CS and/or data iscommunicated through an optical transceiver or opto-coupler comprisingan optical source such as LED or laser, etc. and detector. Thetransceivers can be physically separate from the coils or can occupy thesame space for space saving and/or alignment. For example, they can beplaced at the center of flat coils.

In accordance with an embodiment, the receiver shown in FIGS. 1-4 can bebuilt into or on a mobile device such as a mobile phone, MP3 player,camera, GPS device, Bluetooth headset, laptop, speakers, video monitors,stereo systems, mobile storage device, etc. The receiver may beintegrated into or on a device or battery or into or on a factory orafter- market mobile device battery cover or outside sleeve or skin orcarrier for the device and/or battery. In the case that the receiver canbe integrated in or on a mobile device battery cover or a skin or case,sufficient electrical connections between the mobile device batterycover or back or a skin or a case and the mobile device for carryingpower and any charging signal and/or data should be implemented. Forexample, in FIG. 1, the partition between the parts integrated into oron a mobile device battery cover or back or a skin or case and insidethe mobile device can be along any of the lines shown.

FIG. 5 shows a design for integration of a wireless charger and/or powerreceiver into a mobile device battery cover or back cover in accordancewith an embodiment. The battery can also be powered/charged byconventional wired connection from an AC/DC adaptor or USB or mini USBconnector, etc. The circuitry after the receiver coil shown in FIGS. 1-4can be partitioned into a part on the back cover or mobile devicebattery cover and a section integrated into the mobile device and/or thebattery. The two parts transfer power/signal/data with electricalconnectors/pins in the mobile device back cover or battery cover andcorresponding mating ones in the mobile device and/or battery. Themobile device in this case may also be charged/powered by a wiredcharger/USB cable connection. It may be desirable from a mechanical andsize point of view to have the minimum amount of parts of the receiveron the mobile device battery cover or a skin or a case (such as only thereceiver coil) and the rest of the circuit may reside inside the mobiledevice. On the other hand, for signal integrity purposes and for lowernoise levels, it may be desirable to have many of the parts near thereceiver coil and the resulting dc voltage and any other data lines tobe connected to the mobile device. Thus the connection between themobile device battery cover or back or a skin or a case and the rest ofthe mobile device and/or battery may comprise 1 or 2 to many connectorpins that may carry power and/or charging signals and/or data includinginformation about battery temperature, battery verification, etc. Thisis somewhat atypical of mobile device battery covers or covers or skinsor cases for mobile devices currently used which are typically passiveparts made of plastic, metal, or leather, etc., and have no electricalfunctionality.

In FIG. 5, in accordance with an embodiment, the receiver coil and/orreceiver circuit section can also include additional electromagneticshield layers such as absorbers and/or metal layers and/or ferritelayers and/or heat spreading/and/or heat shield layers to provide betterperformance and reliability.

In addition, to align the receiver coil with the charger and/or powersupply coil, one or a number of magnets can be used. These magnets canbe placed on or around the coil and mounted to be aligned and attractcorresponding ones in the charger and/or power supply to align the coilslaterally to allow maximum efficiency and power transfer. As an example,in FIG. 5, a ring magnet is shown on or around the receiver coil. Thisring magnet can be magnetized perpendicular to the plane and can attracta corresponding and similar magnet in or around the charger and/or powersupply coil to align the two parts. In FIG. 5, an optional gap or breakin the ring is also shown. This gap can serve to limit or eliminate theeddy currents generated in the magnet due to the time varying magneticfield of the charger and/or power supply coil or receiver coil, and hasbeen found experimentally to be quite effective in eliminating wastedpower and heating of the magnet due to the eddy current effect. The ringmagnet is shown as an example and other magnet geometries or othermethods for alignment can be used for alignment of the coils. These mayinclude straight magnets, arc magnets, square magnets, or one or moremagnetic discs or other shapes attached to the receiver coil or mobiledevice battery cover or back of the device, skin, case, etc. andsimilarly incorporated in the charger and/or power supply. The magnetsmay be mounted such that they allow rotation of the receiver coil andthus the mobile device and/or battery with respect to the charger and/orpower supply while maintaining charging capability. Use of the magnetsis especially beneficial in cases where the charger and/or power supplyis integrated or attached to a moving platform such as in a car where itis important to keep the mobile device stationary while the car ismoving.

In order for a mobile device battery cover or back of a device to havethe connectivity to the mobile device and/or battery required, the coveror back may use pins or connectors that can mate with corresponding onesin the mobile device or directly on to the battery of the mobile device.These pins may be of the type that connect when the two parts are slidagainst each other or make an electrical connection when pressedtogether or alike.

Inside the mobile device, the power and charging signal or data from theconnector pins are carried to the rest of the charging/regulation/chargeor power management circuit or IC and may also be connected to the mainprocessor or other circuitry inside the mobile device to provide orreceive data or other information. In the example geometry shown in FIG.4, power from the power management IC (PMIC) inside the mobile device isapplied to the battery connectors and used to charge the battery.

FIG. 6 shows a receiver integrated into a mobile device and/or batterywhich has the capability to be charged wirelessly or by traditionalwired power from an AC/DC adaptor or power supply and/or USB, or anotherdevice or other means.

If the mobile device has both means of wireless and wiredcharging/powering of the mobile device and/or battery as shown in FIG.1-6 above, the power from the wired connector may be connected to thesame battery charger or PMIC in the mobile device and/or the battery andthe PMIC or the mobile device or the regulation, or separate switchingcircuitry. The communication and control circuit may have an algorithmfor deciding which one to over-ride if power is simultaneously availablefrom wired and wireless sources. Switches in the path of power fromeither or both sources may cut off or reduce power from each powersource. In addition, the receiver may provide signaling to the wiredcharger and/or power supply and/or wireless charger and/or power supplycircuit to shut down so only one source of power to the mobile deviceand/or battery is operating and providing power. Similarly, thissignaling path can provide additional signals to combine power or otherfunctions if needed. Other methods for enabling or disabling chargingfrom either source are possible and should be implemented to avoid anyissues in simultaneous charging from two sources.

Additional connections can provide information on the validity and typeof battery, Identification verification, its temperature, state ofhealth, amount of charge or other information. These data can also beshown on the mobile device screen or activate an LED or audible signalor alike through the interface with the main processor in the mobiledevice or other circuitry.

As an example, in a mobile phone, the amount of charge of the batteryand whether it is being charged wirelessly or in a wired manner may beindicated on the main phone display.

In the above example, the power from the receiver and any additionaldata and/or charging signals are carried through connectors between thebattery cover/back cover and the mobile device. It is also possible tohave the connector directly on the battery in the device and thereceiver can connect to it in a similar way. The circuitry of thereceiver necessary to charge the battery and/or perform any CS or datacommunication and any possible alignment magnets and heat or EMI shieldlayers can be partially placed on the back cover and partially on or inthe battery as appropriate.

In accordance with an embodiment, when the mobile device or battery isplaced on or close to the wireless charger and/or power supply, thecharger and/or power supply and the mobile device or battery mayexchange a code or verification and charging or transfer of powercommences. The mobile device and/or battery can also check to see ifsimultaneously power is being received from the wired power connectionand decide which one to accept or even to in some circumstances toaccept power from both sources to charge faster. The charging processmay then in turn activate other functions directly or through the mainprocessor in the mobile device or the host or nearby devices or devicesconnected through the internet or other communication methods such aswireless 3G, GSM, WiMAX, etc. There may also be LEDs, indicators, etc.in the cover or back or case or skin or mobile device display screen orin the charger and/or power supply and/or host device where the chargerand/or power supply is included or connected to (car, train, laptopcomputer, other mobile device storage device, kiosk, clothing, orbriefcase, purse, etc.) or audible signals to provide furtherinformation to the user.

In accordance with an embodiment, the data or CS exchanged betweenvarious devices can: Show start of charging and/or end of charge; Showbattery temperature; Show state and level of battery charge indicator;Communicate data to and from mobile device; Communicate device presenceto charger and/or power supply (or device that the charger and/or powersupply is built into or connected to such as laptop) or nearby devicesor devices connected by internet or other communication methods;Communicate type of charger and/or power supply/environment (wired/orwireless charging and/or power) and from what device (being chargedand/or powered from laptop, car, etc.); Communicate device batterystatus/state of charge, etc. to charger and/or power supply or devicecharger and/or power supply is built into or connected to such as laptopor nearby devices or devices connected by internet or othercommunication methods; Charge and/or power mobile device wirelessly at adifferent rate or speed depending on the charging platform andlocation/type; Perform synchronization or download or upload of data.Synchronization or upload or download can include calendar, contacts, todo lists, new downloaded programs, pictures, movies, music, other data,files, date, time, etc.; Show a list of movies/video/music/pictures thatare available on the device. etc. on host device or nearby devices ordevices over the internet or WAN connection; Verify a mobile device useridentity or credit card, ATM, or other financial information; Charge orbill user for services such as charging or powering and/or otherservices such as use of internet, phone or video calls or download orupload of data, movies, music, ringtones, pictures, or computer ormobile applications or services or online purchases, etc.; Show batterycharge/status on mobile device or host a nearby devices or devicesconnected by internet or other communication methods; Show amount ofmemory used or free on mobile device on host or nearby devices ordevices connected by internet or other communication methods; Show anytasks to be accomplished or emails received or calendar items that thedevice has received on a host or nearby devices or connected by internetor other communication methods; Connect the mobile device and host sothe memory in either one is seen as a directory on the other one and isaccessible; Enable access to the files and directory of the mobiledevice over the internet or by nearby devices; Duplicate the mobiledevice screen on the host, a nearby device, or laptop or nearby devicesor devices connected by internet or other communication methods; Use thebroadband or other connection of host or a nearby device to providecommunication for the mobile device or vice versa; Use Power Linecommunication from host and/or mobile device to provide communicationfor to each other or to other nearby devices or other devices or serversover the internet, etc.; Use the mobile device as a remote controllerfor the charger and/or power supply or the host or a nearby device ordevices connected by internet or other communication method; Use thecharger and/or power supply host or a nearby device or devices connectedby internet or other communication methods as a remote controller orinterface for the mobile device being charged or powered; Use the mobiledevice to change temperature, lighting, shades, etc. in a home, office,or car environment; and/or any combination of the above.

In addition, the charging of the mobile device can activate a number offunctions in the mobile device and or the host or charger and/or powersupply or nearby devices or devices connected by internet or othercommunication method. For example, assume a mobile smart phone/MP3player/camera such as an iPhone or a Blackberry phone is being chargedon a wireless and/or wired charger and/or power supply. Recognizing thatthe mobile device is being charged, the device can, for example:Indicate the wireless or wired charging on its screen; ActivateBluetooth transmitter so that calls coming in can be connected to aBluetooth headset without picking up the phone from the charger and/orpower supply; Activate the speaker phone when calls come in; Rotate theimages on the phone according to how the phone is placed on the Chargerand/or power supply to allow easy viewing; and/or Activate WiFi,Bluetooth, Wireless USB or WiMAX connectivity to connect wirelessly to anearby computer, data gateway, kiosk, or laptop to transfer or syncdata/images/video/music/files/calendars/phone book, etc.

Exchanging a code and/or data between the charger and/or power supplyand the mobile device, the two parts can recognize each other and takeactions that may be pre-programmed by the manufacturer or programmableby the user or can depend on other factors such as day/time/location ofcharging/priority list, etc. This “Contextually Aware” charging may havemany uses and can reconfigure the mobile device or the host (laptop,car, kiosk, other mobile device, etc.) or nearby devices to actdifferently depending on ID received from charger and/or power supplyand/or mobile device.

For example, a mobile device can be programmed to recognize a chargerand/or power supply at home or office and act differently in eachsituation and configure itself to connect to a variety of devices athome or office through appropriate wireless or wired connections such asBluetooth, WiFi, WiMAX, Wireless USB, etc. depending on the preferredcharacteristics and options for the charger and/or power supply and evenconnect with the home or office's computer or stereo or videoentertainment systems to: Log on and authenticate user in the office orhome environment when entering into each area and charging on theappropriate charger and/or power supply commences; Automatically log onto the appropriate WiFi/Wireless USB network; Connect and play musicthrough home or office stereo or nearby speakers; Play movies, etc.through home video system; Synch with computer/download/uploadcontent/music/video, etc.; Act as a wireless modem for connectivity ofcomputers or cell phones nearby; Become the wireless modem for a homeVoice Over IP (VOIP) system; Place the phone on mute in case of a callor ring louder or use a different ring tone, etc.; Transfer all incomingcalls to the home or office (depending on location) landline or VOIPphone automatically; Connect phone with wired broadband Home WiFi systemso calls or Data received or sent go through the wired WiFi system andthe wired Broadband network. This may provide more clear calls or saveon calling charges or provide faster download or upload of Data andfiles; Initiate or activate incoming or outgoing Video calls through themobile phone connection (GSM, 3G, WiMAX, etc.) using external home orcomputer screen or TV and external speakers and microphone; Routeincoming or outgoing Video calls through the home or office WiFi/WiMAXand or fixed DSL, Fiber or other communication system; Duplicate thephone's screen or functions on a home computer so it can be controlledfrom another location. Users may be able to access music or pictures andplay/stop/shuffle from a nearby computer or other mobile device or makeoutgoing calls or control other functions. The functions available mayalso depend on the mobile device being charged and the range offunctions/software interface may change based on the device. Forexample, with a smartphone with many available functions, the interfacecan have many available options while for a simple phone, these can bemore limited; Activate a Bluetooth headset or external or internalspeaker and microphone if a call comes in; and/or Use the charger and/orpower supply host or a device nearby or laptop to dial the phone numberon the mobile phone.

Similarly, in a car environment, identification of the mobile device ona charger and/or power supply in a car can: Activate the mobile deviceto connect to car Bluetooth system automatically so incoming calls areconnected to speakerphone or car speakers and a microphone if call comesin or initiated by user to allow hands free driving; Connect the mobiledevice to car entertainment system wirelessly to: Play music or moviesin car; Play different films for different people in car; Play differentmusic to different Bluetooth headsets; Allow watching TV, podcasts, etc.received through the mobile device; Route video calls to in car videosystem; Have the mobile device synchronize and download or upload musicor other information to storage device in car for entertainment ordiagnostics; Enable mobile device to notify emergency crew in case ofaccident or emergency; Start GPS view or program on the mobile device,etc.; and/or Allow the phone to be the broadband modem that can thenconnect to other mobile devices within car with Bluetooth or WiFi,wireless USB, etc. and authenticate with these devices.

Also, the mobile device presence and wired or wireless charging cantrigger a series of reconfigurations in the car, such as: Set thetemperature to pre-programmed mobile user desired level.; Set the carseat to the right position for the mobile device user; Adjust mirrors tothe right position for mobile device user; Turn on the radio/stereo tospecific favorite station/music; Change driving conditions of car(performance/speed vs. comfort, etc.); Can automatically switch thecontrol for various features on phone to controls available in car or onsteering wheel or a remote controller to: Dial phone numbers, Turnvolume up/down on voice or video calls or music or video/TV, Switchmusic/movie, Fast forward/back/stop, pause, playback, etc.; and/or ifcharger and/or power supply is at an angle or different locations,through either recognition between device and charger and/or powersupply/or through accelerometer, change device displayorientation/function.

In other settings, the authentication can trigger other pre-programmedfunctions. For example in public chargers and/or power supplies, theverification of the presence of mobile device on a charger and/or powersupply can trigger connection to public WiFi or WiMAX systems or on apublic charging kiosks, can authenticate the user and allow download orupload of movies, pictures, music, etc. and even provide method forbilling and charging of the customer for services used.

One will note that many of the functions above (watching TV using themobile device as a receiver, GPS, etc.) and connectivity through WiFi,etc. are quite power hungry and without the simultaneous charging orpowering of the mobile device occurring, cannot be sustained for a longperiod. As another example, downloading or uploading pictures or videosfrom a camera or mobile phone, etc. may take a very long time and drainthe battery without simultaneous charging or powering of the mobiledevice/camera occurring.

In addition, in accordance with various embodiments the charger and/orpower supply and the mobile device may have the followingcharacteristics: Charger and/or power supply pad or stand has one ormore magnets to align with similar magnets in or around the receiver toalign the coils and to keep the device in place; Charger and/or powersupply or stand that is tilted so the user can view the device screenbetter when device is placed on the charger and/or power supply pad orstand; The charger and/or power supply or pad that has a non slipsurface to allow better grip of mobile device when it is placed on thepad or stand; and/or the charger and/or power supply pad or stand thathas an adhesive, magnetic, nonslip, or surface with suction cup on theback so it can be attached at an angle, vertically, or horizontally on asurface.

Improvements in Thermal Performance and Efficiency

In accordance with some embodiments described herein, features can beprovided that overcome several shortcomings of previous approaches,including methods by which the wireless power devices and chargers orpower supplies can provide better thermal performance, better detectionof external objects, and better power transfer efficiencies, and canenable operation at greater distance between charger and receiver coils.

While most of the description below is based on the inductive method,the embodiments described here can be implemented with either theinductive method or the magnetic resonance method for power transfersome of which have been described above. Inductive methods of powertransfer are described below as an example of the more general wirelesspower transfer.

There are several issues that are important in design of a practicalwireless charging system. The charger and receiver for the wirelesscharger system include wound wire coils, PCB or flexible PCB coils, orstamped or etched free-standing coils or deposited on a substrate. Thecoils create and detect the AC magnetic field that is used for powertransfer and communication.

As described in “Coreless Printed Circuit Board (PCB)Transformers—Fundamental Characteristics and Application Potential”, RonHui, S. C. Tang, H. Chung, Vol. 11, P. 3, 2000), a magnetic flux patterncan be generated when, e.g. a 1 cm diameter coil is excited at 8 MHz.When viewed in the horizontal cross section or plane of the coil, thepattern shows the high concentration of the magnetic flux at the centerdecreasing to towards the edge. The resistive heating of the coil due tocurrent and the high amount of the flux at the center and any associatedgenerated eddy currents create a hot spot at the center.

Experimentally, the inventors have found that for a 10 turn 4 Oz. CopperPCB coil on a 0.2 mm FR4 PCB backing with 32 mm outside coil diameterand Inside diameter of 1 mm, operating with 0.5 mm spacing between theCharger and Receiver coils and 2.5 W output power at 5 V (0.5 A).Without any thermal management, the center of the coil can be 20 degreesover room temperature due to resistive heating of the coil. Thesituation is exacerbated by the fact that this center will be a hot spotwhere heat is generated within a small surface area and cannot dissipatelaterally or vertically due to low thermal conductivity FR4 substrate.

While the increase in temperature is not too high for many applications,it is desirable to improve this especially for the receiver that isplaced inside or on a mobile device or battery. The lifetime andreliability of a battery depends on its operating temperature and loweroperating temperatures are highly preferred.

U.S. Patent Publication No. 20090096413, which is incorporated herein byreference, describes use of several methods for reducing thistemperature rise. Two methods described therein involve use of a thermalconductive layer attached or incorporated near the receiver and/orcharger coils to rapidly spread or dissipate any generated heat. Anexample of such a material can be high heat conductivity ceramicmaterial. In addition, we have described the use of metal layers aroundthe coil that will further rapidly conduct any heat away from the coiland spread over a larger surface area to dissipate through convection orheat sinking in other ways. These methods can of course be combined tofurther reduce any effect.

Experimentally, the inventors have found that attachment of a 0.25 or0.5 mm thick ceramic layer to the charger and receiver coil in theconfiguration above reduced the maximum temperature rise at the centerof the coil to 6 to 14° C. depending on whether there was additional airgap between the coils and the power transferred. Addition of highconductivity layers to the coils, however, can increase their thicknessand also increase the manufacturing complexity of the parts which is notdesirable especially inside mobile devices or batteries. In anembodiment, two other methods are provided for reducing this temperatureincrease without increasing the thickness and cost or complexity of theparts.

Another aspect of an embodiment of the invention herein deals withforeign object detection. If a metal object such as a coin is placed onthe charger coil, the charger can begin to heat the object to very highdegrees that can cause burn for the user or failure of the device.

The inductive coils can carry one or more amps. For example. U.S. PatentPublication No. 20080164839 describes the thermal performance of coilswith foreign objects on the surface of the charger. In this example, itwas found that with wire wound helical coils and a metal object such asa coin placed on the charger, the surface temperature of the chargercoil can reach 150° C. and higher at the center within 90 seconds.Different locations on the coil experience different temperatureincreases. In this example, temperature detection sensors were placedbehind the charger coil and monitored this temperature to detect foreignobjects and to ensure that unsafe temperatures were not reached. 75° C.was chosen as the threshold and used to cut off power to the chargercoil. While this strategy is practical, it is best to avoid any powerbeing delivered to the foreign object altogether.

As disclosed herein, a method is described so that, in accordance withsome embodiments, power would not be delivered in such circumstances.Another feature of some embodiments are methods for achieving higherpower transfer efficiencies and distances between the coils.

Recently, by using a higher Quality Factor (Q) resonance circuit, thedistance between a wireless charger and receiver has been increased, asdescribed, for example, in U.S. Patent Publication Nos. 20090015075 and20090033564, and in “Efficient wireless non-radiative mid-range energytransfer” Aristeidis Karalis, John D. Joannopoulos, and Marin Soljacic.Annals of Physics Vol. 323, p.34, (2008). In general, larger distancesare achieved at the expense of efficiency. The above references describea geometry for a magnetic resonance system where a charger coil loop isused to excite a high Q coil and capacitor resonant antenna that getexcited by the charger coil loop and emit RF power in resonance with areceiver resonant antenna that couples power to a Receiver coil loop andto a load. This geometry allows larger coil to coil distance foroperation.

However, some of the drawbacks of the geometry are that: a) The voltagein the LC resonant antenna can reach over 1000 V according to theinventors. This is a high voltage and requires large components that areespecially not desirable in the receiver; b) The system has relativelylow efficiencies of 30% or lower or even 10%; c) Since the distancebetween the coils can be several cm and possibility of human exposure tothe field exists, the maximum magnetic field for such a device in use islimited by regulatory limits on safe exposure limits; d) Due to thelarger travel distance of the fields in this geometry, the magneticfields extend beyond the receiver when integrated into a mobile deviceor battery and can affect the performance of the mobile device orbattery. In addition, any metal layer or wires in this area can affectthe operation. Ideally, one would prefer the fields not to extend beyondthe receiver coil.

As disclosed herein, in accordance with an embodiment, methods areprovided for using resonance to achieve larger operating distancebetween the coils while overcoming some of the issues with geometrydescribed above.

FIG. 7 shows an inductive charging system where the receiver coil (topcoil and its substrate) is integrated into or on a rechargeable battery(FIG. 7 a) or into or on a mobile, electronic, or electric device (FIG.7 b). In these configurations, the coil can be a wound wire coil or aPrinted Circuit Board (PCB) coil.

In the configurations shown in FIG. 7, the magnetic field generated bythe bottom charger coil may extend beyond the coil on the top andinterfere with the operation and performance of the battery or thedevice. In addition, any metal layer in the packaging of the batterycell or in the mobile device may affect the field pattern and magnitude.The time varying magnetic field can also set up eddy currents in metallayers or wires and can cause excessive voltages or heat generation. Inaddition the coils may generate heat during transfer of power due to thecurrent in the windings and the heat may have undesirable effects on thebattery or the device electronics. As disclosed herein, methods aredescribed to improve the power transfer efficiency, effect of metallayers nearby, and thermal and Electromagnetic Interference issuesrelated to design of Inductive and resonant magnetic wireless chargers.

FIG. 8 shows a helical coil and a representative shape for the generatedmagnetic flux by this coil. The temperature distribution would similarlyhave a peak at the center. This is caused by the higher Flux at thispoint as well as the geometric situation where a high heat build up atthe center would be radiating outward to spread in the plane of the coiland would create a hot spot at the center. To address the issue ofthermal heat build up at the center of the coils, two methods arediscussed here. In the first method, the coil is designed so that itdoes not terminate at the center of the circle. FIG. 8 shows a helicalcoil pattern where a peak at the center of the coil for magnetic fluxexists. The resulting temperature distribution will similarly have apeak at the center due to this high flux and also due to the symmetry ofthe geometry and high heat generation at this center which will bespreading in 2 dimensions in the plane. The coil is designed toterminate before reaching the center so the coil has an annular shapeand the magnetic flux (center) does not have a maximum at the center.The flux does not create a hot spot. Therefore the resulting temperatureprofile (right) is lower at the center and lower overall.

In accordance with an embodiment, the coil is designed to have anannular shape with no winding in the middle so that the magnetic flux ismore flat or even lower at the central portion (see FIG. 9). The centralarea also has very small length of wire and therefore contributes littleto the inductance of the overall coil. With an annular shape coil, largeamounts of heat are not generated at the center and the center does notbecome a peak temperature area. This design results in a lower overalltemperature for the coil area and a more distributed temperature profileat the center (see the right figure in FIG. 9).

The inductance of a helical coil pattern is well approximated by:

L=r ² N ²/((2r+2.8d)×10⁵)

where r is the mean radius of the coil in meters. For an evenlydistributed helical coil, this is equivalent to (outer radius+innerradius)/2. d is the inner radius of the coil. d is the depth of coil inmeters which is equivalent to the outer radius minus the inner radius. Nis the number of turns.

Therefore, for an example, for a 10 turn coil starting at the center andending in radius of 16 mm, the calculated inductance is 1 microhenrywhich is similar to measured values.

To design for the same inductance and outer radius, it can be shown that7 turns with the inside loop starting at radius of 5 mm would provide asimilar inductance.

Due to more uniform Flux profile and lower and smoother temperatureprofile, such an annular shaped coil would be preferable in practice.

Therefore, in accordance with an embodiment it is preferred to useinductive coils that have annular shapes with the center area withoutany winding in the center area to reduce the heat generation there.

The inventors have earlier shown methods such as use of metal layersaround the coil to further remove heat from the coil.

FIG. 10 shows the integration of the wire wound or PCB or stand-alonecoil on a metal layer surrounding the coil to remove any heat further.The metal layer can be a layer on a PCB and if the coil is also a PCBcoil, the two parts can be made on the same PCB either on the same layeror different layers to make the manufacturing simple. In addition,alignment magnets to pull the charger and receiver coil into alignmentcan be used. In the right figure in FIG. 10, integration of electronicsand an annular alignment magnet is shown on the same PCB board to allowfurther simple integration.

In the configurations shown in FIG. 10, the magnetic field from the coilmay set up unwanted eddy currents in the surrounding metal layer andshown annular magnet. To overcome these effects, the annular magnet maybe cut or be discontinuous in one or more places as shown in FIG. 8 onthe right to prevent the carriers to circulate around the ring due tothe magnetic field and create unwanted loss and heating.

Similarly, the metal layer can be cut at one or several places to avoidthe possibility of creation of circulating currents in the metalsurrounding the coil. This is shown in FIG. 11. Experimentally, it isfound that placing some cuts in this layer and any alignment magnet suchas the annular one shown prevents undesirable eddy currents andassociated heating of the metal layer.

However, it is still important to distribute the heat generated in thecoil laterally efficiently to avoid local hot spot formation and heatingat the coil. In accordance with an embodiment a method for efficientheat distribution from the coil is provided, without the undesirableeffects of eddy currents.

FIG. 12 shows an embodiment wherein a metal or other thermallyconductive layer is used for heat removal from the coil. In thisconfiguration, the metal layer that is under the coil layer has apattern that has diametrical cuts that prevent circular movement ofcarriers and therefore reduce eddy currents. Other patterns can also beused. In this case, for PCB coils, the coil pattern and the metalpattern can be on different layers with a thin layer of PCB materialsuch as FR4, Polyimide, or other dielectric in between to createelectrical isolation. Ideally, the layers would be separated with adielectric material that has high thermal conductivity and lowelectrical conductivity. The heat that is pulled away and distributedfrom the coil can be further distributed laterally by other metal layerssuch as in FIG. 8 around the coil or by combining this with dielectricor ceramic layer, etc. or other heat sinking methods.

FIG. 13 illustrates the use of heat distribution away from the coil witha metal layer below the coil. The left figure shows an annular coillayer, the center figure shows the heat distribution metal layer. On theright, the metal layer on the coil layer is shown. The 2 layerstypically would have a thin electrically non-conductive layer inbetween. This can be easily created in PCB production by having the coillayer and the metal layer in different layers of a PCB. To avoid eddycurrent generation, the metal layer is discontinuous so carriers cannotcomplete a circular motion round the center of the coil. In thisexample, diametrical cuts in the metal layer prevent the circular motionof carriers while the metal layer effectively distributes heat away fromthe center to the edges where it can be dissipated by convection orconduction or other methods.

In the other embodiments as shown in FIG. 13, the annular coil patterncan be combined with the discontinuous metal layer to further reduce anythermal effects.

FIG. 14 illustrates the use heat distribution away from the coil with ametal layer below the coil. The figure shows the heat distribution metallayer. To avoid eddy current generation, the metal layer isdiscontinuous so carriers cannot complete a circular motion round thecenter of the coil. In this example, diametrical cuts in the metal layerprevent the circular motion of carriers. Additional circular cutsfurther reduce the area that could potentially create eddy currents. Themetal layer effectively distributes heat away from the center to theedges where it can be dissipated by convection or conduction or othermethods.

In FIG. 14, another embodiment is shown where further circular cuts inthe metal layer reduce any possible eddy currents further compared togeometries in FIGS. 12 and 13.

In any of these geometries, the heat would have to cross the areabetween the metal layers that is discontinuous. This transmission couldoccur through the substrate material such as PCB that the metal layer isattached to, a ceramic layer or other layer that may be electricallynonconductive.

FIG. 15 illustrates the use of heat distribution away from the coil witha metal layer below the coil. The figure shows the heat distributionmetal layer. To avoid eddy current generation, the metal layer isdiscontinuous so carriers cannot complete a circular motion round thecenter of the coil. In this example, diametrical cuts in the metal layerprevent the circular motion of carriers. Additional circular cutsfurther reduce the area that could potentially create eddy currents. Tobridge the thermally resistive gap in the metal layer that would affecteffective heat transmission, a second metal layer that is electricallyseparated from the first heat transmission layer can also beincorporated. This layer can have metal layers that cover the gaps inthe first metal layer so it can bridge the thermal gap effectively. Ifthe thickness of dielectric layer between the metal layers is thinnerthan the gap in the pattern in the metal layer, this technique could bequite effective in bridging the thermal gap. The metal layerseffectively distribute heat away from the center to the edges where itcan be dissipated by convection or conduction or other methods.

For the thermal dissipation layers shown here, the minimum gap betweensections are given by the limits of the PCB process used. It may beimportant to electrically isolate the sections to avoid eddy currentgeneration. However, this gap in the metal layer also causes a thermalbarrier to effective heat transmission. One method to improve this is tobridge the thermally resistive gaps with another metal layer that isfabricated on another layer and electrically isolated from the firstthermal distribution layer. An example is shown in FIG. 12 where theother layer separated by a thin dielectric such as used in PCBmanufacture bridges the gaps in the first metal layer to improve thermaldistribution.

The patterns and embodiments shown above are shown as examples and inpractice, a combination of the above methods or other geometries areused to achieve the goals discussed. The heat distribution layers shownare also examples and other patterns that can pull the heat away fromthe coil without affecting or minimally affecting the performance of thecharger can be used.

An additional benefit of the methods described here is that the magneticfield generated by the coil will not extend beyond the metal layer andwill therefore not affect any electronics or other metals beyond this.This can be important in the design of the charger and the integrationof the receiver into a battery, mobile device, or its skin, carrier,battery compartment cover, etc. This technique also reduces extraneousEMI generation.

FIG. 16 illustrates the use of heat distribution away from the coil witha metal layer below the coil. The figure shows the heat distributionmetal layer as slices in a circle pattern. The helical coil forinductive power transfer is also shown. To avoid eddy currentgeneration, the metal layer is discontinuous so carriers cannot completea circular motion round the center of the coil. In this example,diametrical cuts in the metal layer prevent the circular motion ofcarriers. The metal layer is extended beyond the coil to provide removalof heat further from the heat generating coil.

FIG. 16 shows that the metal layer in heat removal can be extendedbeyond the inductive coil pattern so the heat is pulled away from thiscenter and then can be dissipated away through conduction or convectionin contact with other thermally conductive layers. These could includeceramic, polymer, plastic, or even metal layers if attached to the metallayer appropriately to reduce any eddy current effects or can simply bethrough convection of air in contact with the large surface area of themetal.

The extended metallic layer patterns shown in FIGS. 12-16 can be appliedto any coil geometry shown above and combined with other ideas andgeometries presented here to further reduce any heating or EMI effects.

A method for reducing the EM fields behind the coil to minimizeinterference with an electronic device operation or any metal layers ina mobile device or a battery is to use a magnetic material in between acoil such as a receiver coil and any metal directly behind the coil. Useof such materials is common with Near Field Communication (NFC) orFelica receivers in mobile devices. An example is FSF-200 material soldby Maruwa Corporation which is designed to have a high permeability withboth a real and imaginary part.

In accordance with an embodiment, an appropriate material for use as ashield is FSF200 from Maruwa Corp. which is designed for shielding ofNear Field Communication (NFC) or RFID tags that are in contact with ametal backing. The material has high real and significant imaginary(loss component) permeability at the operating frequency of 13.6 MHz.FIG. 17 shows the placement of this material between the substrate forthe antenna coil (marked IC card, IC tag) for the NFC or RFID card and ametal backing material such as a battery case or in case the RFID isattached to a metallic material.

In this case, the material has large μ′ (real part of permeability) andsignificant μ″ (imaginary part of permeability—related to loss) at theoperating frequency of 13.6 MHz. Therefore the magnetic field is highlyconcentrated in the magnetic sheet that is also lossy. In this way, useof a thin layer of magnetic shield of 1 mm to 0.2 mm and belowsignificantly reduces the effect of the metal behind the receiver orantenna coil in this example. Depending on the characteristics needed,one can also engineer material that only have significant realpermeability values without being lossy at the region of interest toallow strong guidance and focusing of the magnetic field withoutsuffering loss. This may be useful for achieving higher inductances andefficiencies in certain designs. For example, for the FSF200 materialshown in FIG. 17, operation at lower frequencies such as 1 MHz wouldallow concentration of magnetic field in the magnetic shield without theloss component. As mentioned above, these material can be engineered tohave the desired μ′ and μ″ values at desired thicknesses to optimizeefficiency and shielding necessary.

It is clear from the above description that the use of such magneticmaterial in combination with metal layers described above can providebetter thermal and electromagnetic performance.

FIG. 18 shows several geometries discussed above. In FIG. 18 a, thebasic coil structure is shown. In FIG. 18 b, the use of magnetic layersto shield the areas above and below the coils form the magnetic field isdemonstrated. FIG. 18 c shows use of a heat spreader layer that could benon electrically conductive such as ceramic or a metal layer designed tominimize eddy current effects such as the method outlined in FIGS. 12-16and other similar embodiments. FIG. 18 d shows how magnetic layers andmetal shields can be combined to provide thermal and electricalshielding. Other combinations of structures are also possible that forexample combine metal and ceramic layers to conduct heat and/or provideelectromagnetic shielding. The choice of the geometry would be dictatedby space, cost, weight, design characteristics, desired thermal andelectrical performance and other criteria.

In any of the geometries discussed here, use of alignment magnets suchas shown in FIGS. 10 and 11 or other geometries are compatible with thegeometries for improved thermal and electromagnetic interferenceperformance and even when magnetic layers are used, the magnets can beplaced outside of the area covered by magnetic layers and therefore notbe affected by them.

FIG. 19 illustrates a charger and receiver for inductive wireless powertransmission with magnetic layer shielding and annular magnet outside ofthe magnet shield layer area.

In FIG. 19, use of a magnetic shield with an annular magnet is shown asan example. Note that the magnet is not covered by the magnetic layerand can provide alignment pull to align the charger and coil magnetswhile the magnetic layer provides shielding of the areas above and belowthe top and bottom coils (respectively) to reduce electromagneticinterference and/or to enhance power transfer efficiency. The top viewand side view are shown in FIGS. 19 a and 19 b.

Other geometries shown above can be combined with magnets to provide thedesired temperature and shielding behavior while providing alignment ofthe coils with the magnets.

Improvements in Charging Devices and/or Batteries

In accordance with some embodiments described herein, a wireless chargersystem or system for transfer of power wirelessly can be provided inseveral different geometries and/or modes.

In accordance with an embodiment, the Receiver in the mobile device orbattery to be charged inductively can be integrated by the manufacturerin to the device, an example of which is shown in FIG. 20. FIG. 20 showsa design for integration of a wireless charger and/or power Receiverinto a mobile device battery cover or back cover in accordance with anembodiment. The battery can also be powered/charged by conventionalwired connection from an AC/DC adaptor or USB or mini USB connector,etc. The circuitry after the receiver coil shown can be partitioned intoa part on the back cover or mobile device battery cover and a sectionintegrated into the mobile device and/or the battery. The two partstransfer power/signal/data with electrical connectors/pins in the mobiledevice back cover or battery cover and corresponding mating ones in themobile device and/or battery. The mobile device in this case can also becharged/powered by a wired charger/USB cable connection.

It may be desirable from a mechanical and size point of view to have theminimum amount of parts of the receiver on the mobile device batterycover or a skin or a case (such as only the receiver coil) and the restof the circuit can reside inside the mobile device. On the other hand,for signal integrity purposes and for lower noise levels, it may bedesirable to have many of the parts near the receiver coil and theresulting dc voltage and any other data lines to be connected to themobile device. Thus the connection between the mobile device batterycover or back or a skin or a case and the rest of the mobile deviceand/or battery can comprise 1 or 2 to many connector pins that can carrypower and/or charging signals and/or data including information aboutbattery temperature, battery verification, etc. This is somewhatatypical of mobile device battery covers or covers or skins or cases formobile devices currently used which are typically passive parts made ofplastic, metal, or leather, etc. and have no electrical functionality.

In FIG. 20, in accordance with an embodiment, the receiver coil and/orreceiver circuit section can also include additional electromagneticshield layers such as absorbers and/or metal layers and/or ferritelayers and/or heat spreading/and/or heat shield layers to provide betterperformance and reliability.

In addition, to align the receiver coil with the charger and/or powersupply coil, one or a number of magnets can be used. These magnets canbe placed on or around the coil and mounted to be aligned and attractcorresponding ones in the charger and/or power supply to align the coilslaterally to allow maximum efficiency and power transfer. As an example,in FIG. 20, a ring magnet is shown on or around the receiver coil. Thisring magnet can be magnetized perpendicular to the plane and wouldattract a corresponding and similar magnet in or around the chargerand/or power supply coil to align the two parts. In FIG. 20, an optionalgap or break in the ring is also shown. This gap can serve to limit oreliminate the eddy currents generated in the magnet due to the timevarying magnetic field of the charger and/or power supply coil orreceiver coil and has been found experimentally to be quite effective ineliminating wasted power and heating of the magnet due to the eddycurrent effect. The ring magnet is shown as an example and other magnetgeometries or other methods for alignment can be used for alignment ofthe coils. These may include straight magnets, arc magnets, squaremagnets, or one or more magnetic discs or other shapes attached to thereceiver coil or mobile device battery cover or back of the device,skin, case, etc. and similarly incorporated in the charger and/or powersupply. The magnets can be mounted such that they allow rotation of thereceiver coil and thus the mobile device and/or battery with respect tothe charger and/or power supply while maintaining charging capability.Use of the magnets is especially beneficial in cases where the chargerand/or power supply is integrated or attached to a moving platform suchas in a car where it is important to keep the mobile device stationarywhile the car is moving.

In order for a mobile device battery cover or back of a device to havethe connectivity to the mobile device and/or battery required, the coveror back can use pins or connectors that mate with corresponding ones inthe mobile device or directly on to the battery of the mobile device.These pins can be of the type that connect when the two parts are slidagainst each other or make an electrical connection when pressedtogether or alike.

Inside the mobile device, the power and charging signal or data from theconnector pins are carried to the rest of the charging/regulation/chargeor power management circuit or IC and may also be connected to the mainprocessor or other circuitry inside the mobile device to provide orreceive data or other information. In the example geometry shown in FIG.21, power from the power management IC (pmic) inside the mobile deviceis applied to the battery connectors and used to charge the battery.

In accordance with another embodiment shown in FIG. 21, the inductiveCoil and Receiver is integrated into or on a battery. In this case, thebattery can be charged directly when placed on the charger or placedinside the device behind a battery cover or door. One or more alignmentmagnets can also be integrated into or on the battery to help inalignment of the Receiver coil with a corresponding charger coil in thecharger. In the case shown, a round magnet is shown that allowsalignment of the charger and battery while the two parts are at anyrotational angle with respect to each other. The magnet can be one pieceor multiple pieces and can include a gap to avoid heating created by themagnetic field of the inductive charger. The battery in this case can bean after-market or original manufacturer battery that would allowwireless inductive charging. The battery contacts make contact withcorresponding contact points in the device to power the device and/orprovide other charging or communication information. The contact can forexample provide information on the battery temperature, whether it ischarged wirelessly or by wired power, state of battery, datacommunication, or other information. Such a battery can also be chargedthrough conventional wired charger or power supplies through theseconnectors. The receiver circuit inside or on the battery can alsoinclude switches so the battery would switch between wired and wirelesscharging paths and can also signal the charger to shut off if a wiredcharger for the battery (through battery contacts) is present.

In accordance with embodiments the receiver can communicate non-chargingdata (communication such as contact list, calendar or other information)with the charger base. In these cases, the data can be transferred tothe device being charged through other connectors on the battery withappropriate corresponding connectors in the device.

The battery and/or the charger can in addition include layers for heatspreading, dissipation or thermal or electromagnetic barriers or layersto increase the efficiency or other feature of the system. These layerscan be metallic, ceramic, magnetic, plastic, conductive layers, etc.that have appropriate properties for achieving performance improvements.The coil in this embodiment can be flat or curved and/or multi-layeredand created on a Printed Circuit Board (PCB) or Flexible PCB, or bestamped or cut from a metal or other type of material film or formed ormanufactured in the appropriate shape and be free-standing (no backing).The coil can be integrated inside or on the outside or surface of thebattery pack.

It may also be desirable for the wireless charger to include additionalcapabilities. For example, the wireless receiver circuit (in or on thebattery in this embodiment) can include WiFi capabilities that thedevice itself lacks. If the battery can communicate with the devicethrough provisioned connector points, then it is capable of enabling thedevice to communicate wirelessly through WiFi.

Another example is that of a mobile phone that has Bluetooth capabilitybut not WiFi. In accordance with embodiments the battery can haveappropriate circuitry to communicate with external devices wirelesslythrough WiFi and transfer the data to the mobile device throughBluetooth. In this way, the wireless receiver can provide a transmissionprotocol translation to enable seamless communication between the mobiledevice and other devices or networks or the charger. Implementation ofsuch additional features is possible in each of the implementationsdiscussed here.

In accordance with an embodiment, the charger shown in FIG. 21 can bepowered through an external power source such as an AC or DC supply orcan itself include a one-time use or rechargeable battery or othermethods such as solar cells or fuel cells or hand crank, etc. to providepower to it. The charger can also include one or more status indicatorsthat show power being applied to the charger, charging occurring, andcharge complete or other features.

In accordance with another embodiment, shown in FIG. 22, the receivercoil and/or the receiver circuit is integrated in the inside or outsideof the device back or battery door. The receiver coil and/or the circuitcan also be integrated into the device back or battery door duringproduction and be for example inside the injection molded battery doorpart. In this embodiment, the power and/or data received by the receivercircuit can be routed to the input power and/or data connector of thedevice through wires that would terminate in a connector or similarpart. The user can enable the device to charge wirelessly by snappingthe cover or battery door in place and plugging the connector into thedevice connector plug. Similar to above embodiments, the receivercircuit and coil can include additional layers of material to reduceelectromagnetic interference, heat, or other undesired effects.

There are several issues that are important in design of a practicalwireless charging system. The charger and receiver for the wirelesscharger system include wound wire coils, PCB or flexible PCB coils, orstamped or etched free-standing coils or deposited on a substrate. Thecoils create and detect the AC magnetic field that is used for powertransfer and communication.

In addition, the connector for the mobile device can, as an option,include an additional connector to allow wired connection of a wiredcharger and/or wired communication. For example for a device with afemale Universal Serial Bus (USB) connector, the connector can have amale USB connector to plug into the device connector to provide powerand/or communication to the device and a female USB or other connectoron the other side or nearby to enable a cable to be plugged in to chargeor power the device wirelessly or to communicate with the device withoutremoving the cable from the device. The receiver circuit and/or theconnector may include appropriate switching circuits to switch betweenwired and wireless charging or power. The receiver circuit and/or theexternal connector may also enable other functions such as dataconnectivity through additional protocols (WiFi, WiMax, NFC, Bluetooth,Wireless USB, etc.) or provide communication protocol translation(Bluetooth to WiFi, etc.) or provide additional functionality (AM, FM orsatellite radio tuner or transmitter, TV tuner, data storage onadditional memory, expanded processing capability, flashlight, bar codescanner, laser display, extra battery power, GPS, external speaker,microphone, etc.) that is desirable by user. As such the receivercircuit can include additional antennas and/or transmitters and/orreceivers.

In accordance with embodiments, the receiver coil and/or circuit can beinside, outside or in a layer (inside an injection molded part forexample) of a cover or door or skin of the device. It can also beintegrated into an external skin or protective cover for a material suchas Neoprene, plastic, leather, cloth or other material covering adevice.

In accordance with another embodiment, the receiver and/or the coil areattachable or stick-on parts that are attached or stuck on the outsideor inside of the device cover or battery door and routed to theconnector. Such an embodiment can allow the same receiver coil and/orcircuit to be used for multiple devices without the need to integrateinto model specific back covers or battery doors. With a thin receivercoil and circuit or a small circuit placed inside the connector plug,such a receiver may be 0.1 mm or thinner and not add much to the devicethickness and may be attached to the inside or outside of the cover orbattery door with adhesive or other methods.

FIG. 23 illustrates a wireless inductive charger and inductive receivercoil and circuit. In this case, the receiver and/or the receiver circuitare attached to the battery surface and routed and connected to thebattery contacts with attachable wires or cable. In accordance with theembodiment shown in FIG. 23, the receiver coil and/or the receivercircuit are attachable or stick-on parts that are directly attached thebattery exterior and the charging power for the battery is routed andconnected to the battery terminals with attachable wires or connectorsthat make electrical contact with these connectors through pressure orelectrically conductive adhesive. The receiver can include magnets foralignment between the receiver and the charger coil and other layers forthermal or electromagnetic properties as described above. In addition,the attachable circuit on the battery may provide additionalcommunication or other capabilities as described above. This methodallows any manufactured battery to be changed to recharge wirelessly.The required battery voltage for typical batteries and/or maximumcapacity or other requirements are pre-programmed into the receivercircuit eliminating the need for any change by the user. For example, alarge number of mobile device batteries use single cell Li-Ion batteriesthat require a specific charging routine that charges the battery to amaximum of 4.2 V. The receive circuit can have this algorithmpre-programmed or contain a charger IC with a Li-Ion charger to enableany single cell Li-Ion battery to be recharged and can be used by avariety of battery sizes and capacities.

Such a method for enabling wireless charging of batteries can also beapplied to batteries with round or other shapes. For example NiMH orNiCd or Li-Ion batteries in AA, AAA, C, D, or 9 V size can be enabled tocharge wirelessly with stick on thin chargers shown above. In the caseof round body batteries, the receiver coil can be manufactured in acurved shape to be able to attached or incorporated into or on the bodyof the battery. Another method for enabling charging of cylindricalbatteries is shown in FIG. 24.

In accordance with the embodiment shown in FIG. 24 for cylindricalbatteries, the Receiver coil can be integrated into one of the endterminals of the battery and the receiver circuit can be placed insidethe body of the battery (shown at bottom in this case) and internallyconnected to the battery terminals to charge the battery. Placement ofthe battery vertically with the coil in proximity to a correspondingactive charger coil can transfer power to the receiver circuit andcharge the battery. In this geometry, the center of the receiver coilcan be connected to a metal contact which serves as the negativeterminal of the battery.

As shown in FIG. 25, in accordance with an embodiment the charger caninclude multiple coils for charging several batteries at the same timeand may contain a variety of methods for alignment of batteries and thecoils such as magnets (FIG. 25 a) or mechanical methods such as slots ortubes for batteries to fit in (FIG. 25 b) for alignment of charger coiland receiver coils of the battery.

Additional Uses and Implementations of Inductive Charging

In accordance with some embodiments described herein, a device isdescribed by which the wireless charger and/or power supply is a devicethat is powered by a power source from another device such as the poweravailable from the USB or PCMCIA port or similar from a laptop computeror a peripheral hub or consumer electronic or communication device suchas a music player, TV, video player, stereo, or car stereo USB or otheroutlets which include power. The charger can also be incorporateddirectly into a battery so that a battery can charge another batterywirelessly. While most of the description below is based on theinductive method, the embodiments described here can be implemented witheither the inductive method or the conductive method or the magneticresonance method, optical, or other methods for power transfer some ofwhich have been described above. Inductive methods of power transfer aredescribed below as an example of the more general wireless powertransfer.

In one embodiment of this approach shown in FIG. 26, a wireless chargerand/or power supply is in the form of a small device that includes a USBconnector and directly connects to the side of a laptop to form aplatform area where a phone, camera, or other mobile device or batterycan be placed and can receive power to operate and/or charge.

In one implementation, in order to provide a compact device, the USBconnector for the wireless charger and/or power supply can be foldedinto the device and can be unfolded during use for plugging into thepower source. In another implementation, the source of the power is thePCMCIA slot in a computer or other device and the wireless charger has aconnector that can slide into the PCMCIA slot and connect to providepower to the wireless charger or power supply.

In a further embodiment to any of the above implementations, thewireless charger and/or power supply further includes an internalbattery so that while it is plugged into an external device for power,the internal battery is being charged. The wireless charger or powersupply can simultaneously be able to charge or power a mobile deviceplaced on or near its surface wirelessly. However, furthermore, the usercan disconnect the device from the power from the device by for exampledisconnecting it from the USB connector of the laptop and use thewireless charger away from any power source by operating it from its owninternal battery power. In this way, a self-powered portable, convenientwireless charger or power supply is implemented. In one embodiment for aPCMCIA port, the charger and/or power supply with its own internalbattery is small and thin enough to fit into a PCMCIA slot and isgenerally stored and carried in the slot and when wireless charging orpowering of a mobile device is needed, the wireless charger and/or powersupply is ejected from the PCMCIA slot and the internal battery in thedevice is used to power the charger and/or power supply to charge amobile device and/or battery. In another embodiment, a wireless chargeris imbedded in a battery so that it can charge another batterywirelessly. The first battery may itself further include a wirelessreceiver so that it can be charged wirelessly. The second battery beingcharged may be of lower, similar or higher capacity than the first. Inany of the embodiments described above, the charger and/or power supplycan be designed to charge one or more devices simultaneously.

In a further embodiment, while a mobile device is placed on the wirelesscharger and/or power supply, the commencement of charging and orpowering simultaneously starts a communication mechanism in the devicepowering the charger and/or power supply to exchange data/synchronize orcommunicate through a wireless method or through the port providingpower to the charger and/or power supply. Examples of wireless methodsof synchronization can include Bluetooth, WiFi, Wireless USB, Zigbee,optical methods, etc. For example by placing a mobile phone on thewireless charger and/or power supply connected to a laptop's USB port,the wireless charger signals the laptop to begin synchronization and thesynchronization program on the laptop launches and through a Bluetoothor WiFi connection with the phone, contact lists, calendars, photos,music, audio files, etc. are synchronized. In another example with acamera, the photos in the camera are automatically downloaded into thelaptop.

The wireless charger and/or power supply system can also include meansof communication through the wireless charger/power system. For examplefor inductive chargers or power supplies, communication of data throughthe power transfer coils can be enabled. In this case, data from and tothe mobile device can transfer to the device providing power to thewireless charger and/or power supply through the inductive coils andthen through the port interface such as USB, PCMCIA, etc. that ispowering the charger and/or power supply. The files that are transferredcan be user data such as photos, music, audio or video files or contactlists, calendars, programs, firmware updates, etc. but can also includeinformation such as level of battery in the mobile device, diagnosticinformation, etc. For example, while a mobile phone or MP3 player ischarging or being powered on a wireless charger and/or power supply padconnected to the USB port of a laptop, the degree of charge of thedevice and its amount of memory use, firmware version, etc. is shown onthe laptop screen. In variations of wireless power systems, thecommunication method between the charger and the receiver for signalingand communication and control and/or regulation of power can be througha wireless, optical, or even a form of wired communication. In thesecases, the same mechanism can be used for data transfer as describedhere.

In an embodiment shown in FIG. 27 for mobile devices such as a mobilephone, MP3 or video player, game station, laptop, tablet computer, bookreader, computer or video or TV display, etc, a wireless charger and/orpower supply is integrated into a stand or holder for such a mobiledevice so that the mobile device can be powered or charged when placedon the stand. A mechanical or magnetic mechanism for attachment orholding of the mobile device or display on such a stand would keep theparts in proximity and alignment for wireless charging. The Receiver forthe wireless charger can be built into the device by the manufacturer,or integrated into a skin or case or a battery for the device.

To use a magnetic method for securing the device on the charger and/orpower supply, one or more magnets can be placed in the charger and/orpower supply and similar magnets or ferromagnetic material in thedevice, its skin, or case or battery can be used to provide anattractive force to align and hold the device in place.

An example of a type of magnet that can be used for this purpose is aring or arc magnet that will provide minimal or no effect on performanceof a wireless charger while providing secure and rotationally invariantalignment and holding power. To reduce or eliminate eddy currents in aring magnet in inductive chargers and or power supplies, a break or cutin the circle prevents creation of circulating currents and is verybeneficial. The ring is used here as an example and other geometries ofthin magnets such as a square, rectangle, triangle, etc. shape can alsobe used.

In many situations, it would be beneficial for the mobile device and/ordisplay to exchange data/information with the charger/power supply andor other devices such as mouse, keyboard, routers, modems, the internet,other displays, speakers, printers, storage devices, or USB hubs, etc.In these cases, a means for data exchange between the mobile device andthe external devices through communication through the stand can beimplemented. Such a communication can be through the wireless charger orother components such as WiFi, Bluetooth, Wireless USB, Powerline, orZigbee communication, etc.

In addition, the wireless charging stand can provide additionalfunctionalities to the user. For example, by placement of the mobiledevice on the charger and/or power supply, the device is automaticallyauthenticated and connection to various peripherals and/or internet isenabled. In addition, the content of the mobile device is replicated ona larger display or the audio is routed to external speakers or speakersbuilt into the stand. Depending on the orientation of the device on thedisplay, the display on the mobile device and/or display can also rotateits orientation to appear in the correct orientation for the user.

For mobile device, Notepad, or tablet users, a keyboard would be ofgreat use in combination with the stand discussed above. FIG. 28 shows afurther embodiment of a charger/power stand which could in additionincorporate an area for charging/powering a keyboard and/or a mouseand/or joystick or remote control and/or other mobile devices such asmobile phone, MP3 player, camera, game player, remote control, battery,etc. The keyboard and/or mouse can incorporate a rechargeable batteryand the keyboard and/or mouse can be stored on the corresponding chargersurface when not in use or even during use. Communication between thekeyboard and/or the mouse and one or more of the mobile devices,notepad, tablet or display can be through one of the established methodssuch as WiFi, Bluetooth, Wireless USB, Zigbee, etc. or through aproprietary method. In addition, the stand can incorporate speakers somusic or audio from one or more of the mobile devices can be playedthrough them.

In another embodiment, the wireless receiver for the mobile device caninclude further functionalities that enhance the use of the mobiledevice. Some examples are given here. In one example, to enable a mobiledevice to receive power wirelessly, a case, battery door, or attachmentto the mobile device includes a receiver for the mobile device and meansof providing power to the battery in the mobile device but also includesa battery itself that is charged wirelessly simultaneously. When themobile device and the receiver are not in the vicinity of the wirelesscharger and/or mobile device, the rechargeable battery included with thereceiver is a secondary battery that powers the mobile device or chargesthe battery of the mobile device to extend the useful time of use of themobile device. An example is shown in FIG. 29 and FIG. 30, where a skinor case for a mobile phone includes a rechargeable battery and connectorfor the mobile phone. When the skin/case is attached to the phone andthe phone and case are placed on a wireless charger and/or power supply,the mobile phone is charged but also the battery within the case/skin ischarged. Once the mobile phone and the case/skin is no longer in thevicinity of the wireless charger, the battery in the skin/case canoperate the mobile phone prior to the internal battery powering thephone or the case/skin battery can provide power once the internalbattery to the phone is exhausted thereby extending use time. The switchover between batteries can be automatic or through the intervention ofthe user by a physical switch or software on the mobile device. While askin/case is shown here, the battery can also be integrated into abattery door for the mobile device or be connected to the power port ofthe mobile device through a cable or alike.

In any of the embodiments described here, alignment of coils in aninductive system is important to allow high efficiency and operation.Use of magnets in the wireless charger and the receiver can achieve thisfunction without any physical features or alignment mechanisms. However,some of the mobile devices can have components such as electroniccompasses that may be disturbed by the use of magnets in the chargerand/or receiver. To reduce or eliminate such an undesired effect, it isimportant to shield the mobile device from the magnetic field. This canbe achieved by incorporating faraday shields or one or more layers ofshielding material such as Iron or Nickel or other Ferromagnetic sheetsor ferrite material or special magnetic material such as mu-metal (aniron/nickel and other material alloy with very high permeability) orNETIC or Co-NETIC material (from magnetic shield corporation) or ceramicor nano materials for magnetic shielding into the receiver skin or caseor the mobile device or battery so that the sensitive components areshielded from stray magnetic field. In the case of the receiver typeshown in FIG. 29, such shielding material can be placed between the coiland the inner surface of the case. In addition, the AC magnetic filedgenerated by the wireless charger may interfere with other devicefunctionalities and can be shielded by incorporation or ferrite or nanomagnetic material into the back of the receiver coil. Such a shield forAC magnetic field can be effective for shielding the DC magnetic fieldas well. Otherwise, it may be desirable to incorporate 2 or moredifferent types of shield layers.

In another embodiment, the receiver is built into other devices thatenhance the functionality of a mobile device. For example, externalmodules, skins, or cases for mobile phones that add TV watching orreception, Radio reception, magnetic reading, Bluetooth connectivity,Global Positioning System (GPS), Universal remote control, Near FieldCommunication (NFC) or extended storage or connectivity capabilitiesexist. Any of these cases or skins or modules that plug into the powerand or connectivity of the mobile device or phone can include a wirelessreceiver so that the battery inside these modules and/or the mobiledevice or phone can be charged or powered wirelessly thereby greatlybenefiting the user.

Additionally, currently, modules for extending the usefulness of amobile device as stick on or attachments or integrated into mobiledevice skin or case or battery door that provide additionalfunctionality exist. Some of these modules can include internalbatteries that require charging. Examples include stick-on or mobilephone case circuitry and antenna that boost a mobile phone reception orstick on circuits for mobile phones that includes Near FieldCommunication (NFC) circuitry and coil for mobile devices that do nothave this capability built in. To communicate this information to themobile device, the sticker can communicate the NFC data to the mobiledevice in another protocol such as Bluetooth or WiFi or Wireless USB,etc. thus translating between the protocols. The sticker can furtherinclude a rechargeable battery for powering the circuitry. In anotherimplementation described here, the sticker described here can include awireless charger receiver and its sticker's rechargeable battery can becharged or powered by a wireless charger remotely thus providing longoperation life.

In another implementation, such a reception booster, or NFCreader/writer, their coil(s) and the WiFi or Bluetooth circuitry can beintegrated into an aftermarket battery for mobile device that includes awireless charging receiver. In this way, a mobile device such as aphone's battery can be replaced with such a battery to provide wirelesscharging receiver capability and extended range or reception and NFCcapability together to a phone user thus providing much morefunctionality.

In some embodiments an aftermarket wireless charger or power supplyreceiver unit can be provided that includes all the necessary receivercoil and circuitry for receipt of power in a thin profile that can beplaced on top of a mobile battery and connects to the battery connectorswith wires, flexible circuit board, or connector cable so that anoriginal battery is enabled to receive power wirelessly whilesimultaneously still operating in its original housing within thebattery compartment of the mobile device. This method can providewireless power charging for mobile devices without affecting othercharacteristics and size/shape of the device and would be greatlyuseful. Additional functionality such as NFC or NFC to Bluetooth or WiFicapability can also be incorporated into such a battery sticker toprovide even more functionality and can draw power form the mobiledevice battery for its operation thereby eliminating the need foranother battery to power the circuit.

Improvements in Charging Efficiency and Other Features

In accordance with some embodiments described herein, features can beprovided to improve charging efficiency, usage, and other features.

For example, in the implementation shown above in FIG. 26, in order toprovide a compact device, a wireless charger/power supply is implementedsuch that it can fit into an area in an electronic device such as adesktop or notebook computer or electronic book or similar. Such acharger and/or power supply can be powered internally by the electronicdevice. Extending the charger and/or power supply outward (similar toejecting a caddy on a CD-ROM or DVD-ROM player or recorder, can startthe operation of the charger and/or power supply and provide the user asurface for charging/powering a mobile device and/or battery. In oneembodiment, such a charger and/or power supply can be built for the sizeand shape of existing available slots on desktop or notebook computersor other devices such as PCMCIA slots or storage devices such as opticaldrives such as CD-ROM or DVD players and recorders and use the existingpower ports available in connectors for such devices or have one or moreseparate connectors specifically for its own operation. In such anembodiment, the charger and/or power supply can be integrated with thelaptop or notebook computer software and/or hardware and perform moreadvanced functions. An example can be that when a mobile device such asa phone with an appropriate wireless receiver is placed on such acharger and/or power supply area, the charging and/or supply of power isstarted and in addition, the mobile phone is synchronized with thedesktop or notebook computer and data such as contact lists, calendars,email, pictures, music, etc. are synchronized. Such a data communicationcan be implemented through data exchange in the charger link such asdata communication through the coils in inductive charging or throughanother established data communication protocol such as Bluetooth orWiFi, Zigbee, or wireless USB, etc.

In another embodiment, the charger and/or power supply described abovecan be removable and/or retractable. As an example, many mobile devicessuch as desktop and notebook computers have slots for removable opticaldrives such as CD-ROM or DVD players or recorders. These components canbe made removable so the user can leave them behind when not in use tosave weight or they are constructed such that the slot can be used formultiple purposes. For example, a slot can be provided in a notebookcomputer where the slot can be used with a removable optical driveaccessory or be used for an additional battery to extend the operatingtime of the notebook computer. Furthermore, the optical drive typicallyincludes a caddy that is retractable and with a mechanical or softwareeject, can extend a caddy away from the notebook computer for the userto place a CD-Rom or DVD or similar media in the caddy. A similarmechanism can be implemented to extend the charger and/or power supplysurface out from the notebook when in use and to retract into thenotebook when not needed. For example, the device shown in FIG. 26 caninclude a wireless charger and/or power supply incorporated into anoptical drive slot. Such slots typically have internal connections thatprovide connectivity between the accessory and internal data or power orbattery lines of the notebook computer. Same connectors or otherconnectors can be provided for the removable wireless charger and/orpower supply to operate. As described above, such a removable wirelesscharger and/or power supply can in addition provide data connectivity ortrigger data connectivity with the desktop or notebook computer and themobile device or battery being charged.

In a further implementation, such a wireless charger and/or power supplyfurther includes internal batteries and/or data storage capability sothat when the charger and/or power supply is plugged in or inserted intoa desktop or notebook computer, the internal battery of the chargerand/or power supply is charged and data from the internal storage deviceis synchronized. The user can also remove the part from the desktop ornotebook computer and operate the part and charge or provide power toother mobile devices while operating the charger and/or power supplyfrom its own internal battery without or with little assistance fromother power sources. This would provide a highly useful portable devicefor providing power and/or charging to mobile devices in varioussituations.

In some cases, it is highly desirable for mobile devices such asnotebook computers, etc. to be chargeable wirelessly. To enable this, inone implementation, an accessory or charger and/or power supply devicethat fits into a slot or available space in a notebook computer or othermobile device is created such that the charger and/or power supplydevice includes a receiver coil and the appropriate receiver electronicsto enable the charger and/or power supply to receive power wirelesslyfrom a charger and/or power supply outside the device. As an example,for notebook computers, a receiver coil and receiver electronics can bebuilt into a PCMCIA or optical drive size and shape so that in the caseof a notebook computer with such a slot, the coil and receiver can befit into the notebook and allow it to be charged or powered from awireless charger and/or power supply pad or surface under the laptop.The receiver coil may include appropriate Electromagnetic shielding orthermal layers to reduce any effect of the electromagnetic field or heaton any internal components of the notebook computer. The connectivitybetween such a wireless charger and or power supply and the notebook canbe provided by provisioned or existing connectors inside the notebookcomputer. An example of this can be a slot provided in a notebookcomputer that may serve one or more purposes of operation with anoptical drive and/or extended use battery. A removable or fixed receivercoil and electronics that would fit into such a slot would allow thenotebook computer to be wirelessly charged from below the notebookcomputer. Such a wireless charger and/or power supply is shown in FIG.31. In one embodiment, such a charger and/or power supply coil andreceiver can be incorporated into a removable or built in optical driveso the same slot can provide 2 functions (charging/power receiver andoptical drive). As discussed earlier, similarly, some removablebatteries for such slots exist for some notebooks. The receiver coil andelectronics can be integrated into such a battery to charge it directlyor charge and/or power the notebook computer.

It is also possible to combine the wireless charger and/or power supplyreceiver and the wireless charger and/or power supply together in oneembodiment so the same device can receive and/or transmit wirelesspower. As an example, a device that fits into an optical drive slot canreceive power wirelessly from below but also have a caddy compartmentthat can be extended or ejected to allow for one or more mobile devicesto be charged wirelessly while placed on or near such a charger and/orpower supply.

In any of the embodiments described above, the wireless charger/powersupply and/or the wireless receiver can include visual and/or audio orother means of notifying the user about commencement of charging/power,end of charging/power and/or degree of battery charge or otherdiagnostic information such as any faults, over-temperature, etc. Thisinformation can be presented on or near the wireless charger/powersupply or receiver or displayed on the computer screen through theinformation being transmitted to the desktop or notebook computer oreven transmitted to another location for display or processing.

In any of the embodiments described here, alignment of coils in aninductive system is important to allow high efficiency and power inoperation. Use of one or more magnets in the wireless charger and thereceiver can achieve this function without any physical features oralignment mechanisms. To use a magnetic method for securing the deviceon the charger and/or power supply, one or more magnets can be placed inthe charger and/or power supply and similar magnets or ferromagneticmaterial in the device, its skin, or case or battery can be used toprovide an attractive force to align and hold the device in place.

An example of a type of magnet that can be used for this purpose is aring or arc magnet that will provide minimal or no effect on performanceof a wireless charger while providing secure and rotationally invariantalignment and holding power. To reduce or eliminate eddy currents in aring magnet in inductive chargers and or power supplies, a break or cutin the circle prevents creation of circulating currents and is verybeneficial. The ring is used here as an example and other geometries ofthin magnets such as a square, rectangle, triangle, etc. shape can alsobe used.

FIG. 32 shows another embodiment where the wireless receiver coil and/orelectronics are housed in a device (shown as a flat part in this image)that is attached to the bottom of a notebook computer through aconnector that exists in many laptops for docking. The connector canalso be used to secure the receiver coil and/or part to the notebookcomputer. The combination of the notebook computer and the receiver(attached to each other), can be placed on a wireless charger surface ordevice and the received power is transferred to the notebook through theconnector. The receiver part may also contain rechargeable batteries toincrease the operational run time of the notebook. In addition, otherfeatures or functions such as an optical drive, additional communicationcapabilities, speakers, extra processors, means for cooling the notebookcomputer, etc. can be included in this part to provide even morefunctionality to the user.

Another implementation for wireless charging in mobile device comprisesincorporating a wireless receiver coil and associated receiverelectronics into a rechargeable battery. This can be useful for mobiledevices so that a device such as mobile phone, walkie-talkie, cordlessphone, camera, MP3 player, notebook computer, or other electronic deviceuser can replace the existing battery in a device with a similar batterywith built in wireless receiver and be able to charge/power the mobiledevice wirelessly. It may be desirable for the battery to be able tocontinue the ability to charge through the internal charger of thedevice when the device is plugged into electricity as well. FIG. 33shows a typical configuration for the circuitry included in commonLi-Ion batteries. A Li-Ion battery pack typically includes a batteryprotection circuit against over-current charge and discharge comprisestypically two back to back FETs. In addition, circuitry to allow themobile device such as mobile phone, laptop or notebook computer etc. tomeasure the amount of charge in the battery can be included. The batteryis designed to work with the charging and “gas gauging” circuitry insidethe mobile device to charge/discharge the battery appropriately and toaccurately reflect the state of charge of the battery and remainingpower. In addition, the circuitry inside the battery may contain meansof measuring the battery temperature such as thermistors to ensureoperation within a safe range. The circuitry may contain amicrocontroller unit to measure and influence charging/dischargingbehavior.

In some cases, a battery may contain specialized circuitry as shown inFIG. 34 to provide battery ID or authentication. The microcontrollershown here is from Microchip Corporation. Data I/O line inside thebattery pack is connected through battery contacts to the device and isqueried by the device circuitry for authentication. This authenticationcan be implemented by device manufacturer to guarantee batteryperformance, quality or for commercial reasons to preventcounterfeiting, etc. A common way to authenticate a battery and ensureit is from a valid source is with a challenge/response system.Challenge/response authentication circuits, also known as identifyfriend or foe (IFF) circuits. The system is implemented so that one partof the system, the host (typically the mobile device), issues achallenge to the other part of the system, the token (e.g. battery),when the two components begin to communicate. After the challenge isreceived, the token calculates a response and transmits the results backto the host system. The direction of the challenge and response can bereversed or even transmitted in both directions. Additionally, eitherside of the system can randomly transmit the challenge and response atvarying times to increase the security of the authentication process.

A battery may include protection IC and/or battery ID (authentication)and/or temperature sensor circuitry inside the battery pack.

Wireless charging can be used with mobile devices in several ways. Toenable a mobile device to be charged wirelessly, the wireless chargingmodule can be incorporated into a battery door or an external case orskin for a device and the wireless receiver can be designed to provideregulated power to the input power jack of the mobile device through apower connector integrated into the case or battery door. In this case,it may be necessary to allow the user to access the other featuresavailable through the same device connector. For example, a mobile phonemay include a USB connector that is used for charging the mobile deviceand for data connectivity. A stand alone charger with a USB connectorwould use the power connectors of the USB to provide power to thedevice. But the user can also connect the phone to a notebook computeror other device with a USB cable and be able to exchangeinformation/synchronize with the notebook computer and at the same timecharge/power the mobile phone.

To implement the wireless charger case or battery door as describedabove, it can be preferable to enable the user to be able to be able tocharge the mobile device wirelessly through integration of receiver intothe case but also allow the user to access the power/data connector onthe mobile device for data transfer/synchronization or wired charging ifdesired. An implementation for this type of wireless charging receiveris shown in FIG. 35.

In this implementation, the case or battery door includes a mobiledevice connector that mates with mobile devices connector and providespower and/or data to the mobile device through. The wireless powerreceived by the wireless charger is regulated in the receiver and/orcharger or a combination of the two and then routed to the powercontacts of the mobile device through a switching mechanism. Thewireless charger case or battery door can also include a wired connectorthat can allow the user to plug in a cable to connect the case to anexternal wired charger and/or cable for charging and data connectivityto other mobile device such as notebook computer. The power lines ofthis connector can be routed to the switching mechanism that routes thepower to the output connector of the mobile device skin. The user may inthis way be able to charge/power the mobile device in a wireless mannerby placing the mobile device and the case or battery door on or near awireless charger device. The Switch can be implemented such that itwould provide charging/power priority to either the wired or wirelesscharger. For example, a user may place the mobile device and the case orbattery door on a wireless charger/power supply and at the same time,plug the case or battery door into an external wired charger and/orwired charging/data device such as a notebook or desktop computer. Inthis case, it is necessary to provide a means to resolve the conflictbetween the two charging paths. The switching mechanism provides this byallowing one path to have priority over the other. For example, if themobile device is placed on or near the wireless charger and at the sametime, the wired charger/power path is connected to power, the switch canprovide priority to the wired method and route that power to theconnector the mobile device. At the same time, the switch may provide asignal to the wireless charger receiver to shut off wireless powerthrough shutting down the wireless receiver and/or charger. For example,a signal can be sent by the switch to the wireless receiver and then tothe wireless charger to shut down the charger until the wired chargingpower is no longer applied. Alternatively, the switch can be implementedto provide priority to the wireless charger so that even when both wiredand wireless charging power are present at the switch, the wirelesscharger output is routed to the mobile device connector. Alternativelypriority can be given to either wireless or wired method afterdetermining which one can provide higher current and therefore fastercharging times or some other criteria.

In addition, the wired connector can also include data lines that can berouted directly or through a circuit to the mobile device connectorintegrated into the case. So that when the case is connected to externalwired power and data, the data lines are routed to the correct dataconnections on the case connector. This would allow synchronization/datatransfer between the mobile device and the device connected to the wiredconnector (such as notebook or desktop computer) to occur without theuser needing to remove the mobile device from the case. In the casewhere the external wired power and data connector is a Universal SerialBus (USB) connector, the data lines correspond to D₊ and D⁻ lines of theUSB protocol.

FIG. 36 shows an implementation of such a case or battery door for amobile device such a mobile phone. The case or battery door includes areceiver coil and receiver and switching circuitry. The output of thiscircuitry is routed to the case or battery door connector to mate withthe matching connectors on the mobile device. In this case, theconnector is shown as a pass through that allows the user to connect awired cable for power/data to the connector and the data lines can berouted to the appropriate connector lines on the opposite side where theconnector mates with the mobile device. At the same time, the powerlines of the wired power/data connector are routed to the mobile deviceconnector through a switching circuit on the receiver circuit or insidethe connector that will function as described above. Furthermore, thewireless charger case or battery door may incorporate alignment magnetsto align the wireless receiver coil in the case or battery door withcorresponding magnets in the charger. These magnets can be flat disks atthe center of the coils or ring magnets in or around the coil ormultiple magnets inside or outside the coil area. They may furtherinclude features to reduce any effect of a magnetic field. For example,for ring magnets, the circle can be disrupted by a cut in the circularshape so that current flow in a circular pattern due to a pulsingmagnetic field (eddy currents) is disrupted. In addition, the case orbattery door may include layers in the coil or behind it to provideshielding form the magnetic field or any generated heat to the mobiledevice or its battery. Examples can include metal layers incorporatedinto PCB coil backs, separate metal layers, ferrite layers,ferrite/plastic compounds, nanomaterials, or other materials designedfor shielding purposes that can be tailored for this application. Inaddition, the receiver circuitry may include thermal sensors (such asthermistors) at various locations (coil, circuit, etc.) to monitor thetemperature of the receiver and ensure safe operation. The informationfrom the sensor can be used to shut down the wireless or wired charger,reduce the current output, and/or provide a warning or alarm to user ortake other actions.

Another method for integration of wireless receivers into mobile devicesis for device manufacturers to incorporate the methods described aboveinto the mobile device during manufacture. In this manner, tighterintegration of functionality with device operation and function can beachieved.

In another implementation, the wireless receiver coil and/or circuit canbe incorporated into a rechargeable battery that can be charged directlyon the wireless charger or when inserted to a mobile device when deviceis placed on or near wireless charger.

As an example, FIG. 37 shows the receiver coil and circuit integratedinto a mobile phone battery. When the battery is inserted into a mobiledevice and the device is placed on a wired charger, the battery canreceive power wirelessly from the charger. However, in many cases, itmay be necessary to allow the user to continue charging and or poweringthe mobile device through wired methods as well. Similar to the mobiledevice case/battery door implementation discussed above, a method toallow both types of charging is necessary.

To integrate a wireless charger into a battery for a mobile device, itmay be necessary to enable the battery to charge wirelessly through itsintegrated receiver coil and receiver circuit (including optionalcharger IC) or through the battery contacts by the external wiredbattery charger through mobile device contacts and optional internalcharge management and/or charge measurement/gauge IC. FIG. 38 shows theblock diagram of major components of such a system.

As shown in FIG. 38, the wirelessly chargeable battery pack may includeone or more battery cells, battery protection and/or ID circuit and/ortemperature sensors such as thermistors as described above, a wirelesscharger coil, wireless charger receiver circuit, optional batterycharger IC (which incorporates an appropriate battery charging algorithmfor the battery cell to provide the correct charging voltage and/orcurrent during the entire charging cycle) and or possibly battery gasgauging (to estimate how much power remains in the battery) and/orappropriate thermal sensors/circuitry. In addition, the battery pack caninclude alignment magnets and/or magnetic and/or thermal shield layersas discussed above.

The path for wireless charging current when the battery is inserted intoa mobile device and the device is placed on or near a wireless chargeris shown in FIG. 38 with dashed lines. The wireless charger receivercircuit may provide power to the optional charger IC which is in turnconnected to a switching circuit. Alternatively, the receiver circuitmay include battery charging algorithm so that it can directly charge abattery or power the mobile device. The output of the switch isconnected to the battery cell contacts through an optional batteryprotection circuit and/or battery ID circuit. Optionally, the output canbe connected to directly power the mobile device which may include itsown charge management and/or gas gauge and or battery ID circuit. Thebattery can be designed such that it would interact with the mobiledevice ID detection circuit to verify the battery and also interfaceproperly with the mobile device charge management and/or gas gaugeand/or temperature sense circuitry.

FIG. 39 shows the flow of current (in dashed lines) when the mobiledevice is plugged into an external wired charger and or charger/datacable and another device such as a notebook or desktop computer. Theexternal charger/power supply can provide power to charge the batteryand/or power the mobile device depending on the state of charge of thebattery and/or the design of the internal charger circuitry of themobile device. The mobile device charge management IC shown can includean algorithm and circuitry to charge the wirelessly chargeable batterythrough its contacts. In this case, the switch inside the battery can bedesigned to route the optional mobile device charger IC circuit outputto charge the battery as shown. The battery may also contain appropriatecircuitry for battery protection, thermal protection, battery ID, etc.In case of an over-temperature condition at the battery, the receivercan take action such as shut down wired or wireless charger, disconnectinput power to the battery, reduce output current for charging thebattery, provide a visual or audible or signal alarm, or otherappropriate actions to ensure safe operation and charging of battery.The thermal sensor or sensors can be placed on or near the battery, thewireless charging coil, critical components of the circuitry, close tothe mobile device interface, etc. or a combination of the above.

The switch in the battery can be designed to provide charging priorityto the wired or wireless charging method. For example, if the mobiledevice and the wirelessly chargeable battery are placed on or near awireless charger and the device is plugged in to a wired charger orwired data/power device such as a desktop or notebook computer, theswitch can be configured to provide priority to the wired charger andshut off the wireless charger through a signal to the wireless receiver,charger, or both. In addition, the wireless charger receiver can signalthe charger to shut off. Alternatively priority can be given to wirelesscharger/power supply over the wired charger/power supply or priority canbe given to either method after determining which one can provide highercurrent and therefore faster charging times or some other criteria.

FIG. 40 and FIG. 41 show implementations of a wireless chargeablebattery for mobile devices as described above. The battery may include areceiver coil on its top surface (close to wireless charger whendevice/battery is placed on or near a wireless charger), optionalalignment magnet or magnets, electromagnetic and/or heat shield layers,and receiver and/or battery protection and/or battery ID, and/orswitching circuitry. To minimize the effect on battery capacity ofintegration of the circuitry into it, the circuitry can be placed on thethin edge of a battery such as a mobile phone or other mobile devicebattery.

FIG. 42 shows a side view of the battery with various layers of thereceiver coil, optional heat, electromagnetic shield and/or optionalalignment magnet or magnets shown. To maximize impact of integration ofwireless charging coil and receiver and other circuitry into the batterypack, it is important to keep the reduction in battery volume due tothese parts to a minimum. It may be therefore important to use thethinnest receiver coil and electromagnetic/heat shields. PCB coils withthin base material (e.g. FR4) or flexible PCB (e.g. polyimide) or freestanding copper coil patterns or wires can be used. This thickness canbe 0.2 mm or below. Metal and/or electromagnetic shielding material withthicknesses of 0.1 mm or lower may also be used. In addition, if one ormore magnets are used, they may add to the overall thickness of thestack or they can be arranged such that their thickness does not add tothe overall thickness.

FIG. 43 shows a case where an alignment disk magnet is incorporated intothe center of a coil in a manner not to increase the overall thicknessof the receiver coil/shield layer/magnet stack. In this case thewireless charging coil has an outer and inner radius and does not fill awhole circular shape. The coil and/or the shield material behind it maytherefore be hollow at the center. It is therefore possible to place adisk or other shape magnet in the center of the coil so that thethickness of the magnet fills the void or takes up some of the space inthis center without adding to the overall thickness of the stack. In anembodiment where the coil is a pcb coil, the center of the pcb may havea cut out area such as a circular hole or aperture where the magnet maybe placed. The optional electromagnetic and/or heat shield behind thecoil may also have a similar hole or aperture.

FIG. 44 and FIG. 45 show other implementations with annular or ring orarc alignment magnets whereby the magnet is on the outside of thereceiver coil and the coil and/or the electromagnetic/heat shield layerscan fit inside the ring or annular or arc magnets between the coil andthe battery cell. In this way, the thickness of the various componentson top of the battery do not add to each other and the overall stackthickness is given by coil plus the electromagnetic and/or heat shieldlayer or the magnet thickness whichever is greater. This would allow thebattery to retain maximum capacity density for a given volume. The ringor annular or arc magnets have the advantage over the central magnetshown in FIG. 43 because they allow much more alignment tolerance andcan exert an alignment pull force over a larger lateral area on acorresponding magnet or magnets in a wireless charger. In addition, byintroducing a gap or cut in the circumference of a ring magnet so thatit is not fully continuous or by use of one or more arc magnets, anypotential eddy currents in the magnet induced due to the alternatingmagnetic field of the wireless charger are reduced or eliminated therebygreatly increasing the effectiveness of these types of magnets for coilalignment purposes. The corresponding alignment magnet in the chargercan be a ring, cut ring, or arc magnet and can provide rotationalinvariance when the receiver magnet and the charger magnet are aligned.An arc magnet in the receiver can be used with a ring or cut ring magnetin the charger or vice versa and will allow full rotational positioningbetween the charger and receiver.

In any of the implementations above, management of the generated heatand thermal issues are important. To reduce the effect of heatgeneration from the coils, it may be desirable to increase the thicknessof the copper layer used in a PCB or use thicker wires in wound coils.For the case of PCB coils, in addition, it is possible to createmulti-layer PCB coils such that several layers of PCB coils areconnected in parallel and produce a resistance that is lower than asingle layer thus reducing resistive heating.

In addition, heat transfer layers can be incorporated to spread the heatgenerated. Such layers need to be designed not to interfere with theoperation of the coils. Since alternating magnetic fields are generatedand detected in an inductive system, use of a metal layer behind thecoil would produce eddy currents and loss. One method for providingthermal conductivity with metal layers is shown in FIG. 46 where a metallayer with discontinuous portions is placed behind and/or around thecoil. In this case, the metal layer comprises rectangular slices thatcan conduct heat away from the center of a coil while due todiscontinuity between the slices, the electrons cannot flow in acircular motion due to the alternating magnetic field. The patterndescribed here has a number of triangular slices but any other patternwhich can provide heat transport but does not allow carriers tocirculate in a rotational pattern due to the alternating magnetic fieldcan be implemented. In FIG. 46, a coil with an inner radius of zero isshown. The coil may have a non-zero inner radius thus leaving a centralportion that has no coil pattern. This may reduce thermal and/or eddycurrent effects on the coil and be preferable.

FIG. 47 shows an implementation where the heat transfer layer isimplemented on the same layer as the coil or is constructed not tooverlap the coil structure. This can be used in cases where each layerof a PCB contains a coil structure such as when a two or more layeredPCB contains two or more layers of coils in parallel to reduceresistance or two coils are placed on the two sides of a PCB to providea center-tapped coil pattern or other geometries or simply when a singlesided PCB structure is used and a heat transfer layer on the same sideis desired. In this case, the coil is terminated with an inner radiusthat allows a central portion without the coil for better heat transferand/or lower eddy current effects. However, this inner radius can bezero as shown in FIG. 46 as well. In either case, in thisimplementation, any potential heat generated at the coil is distributedby the metallic pattern outside of the coil to surrounding areas withoutallowing generation of circular eddy currents due to the alternatinginductive magnetic fields. The heat transfer pattern can be any patternthat reduces or eliminates the possibility of circular motion ofcarriers or electrons around the coil. The heat transfer layer isseparated by a finite gap from the metal coil layer to avoid electricalcontact but the gap should preferably be kept small to allow efficientheat transfer between the two sections. To improve transfer of heatacross the gap, several additional techniques can be used. This includesa PCB base material with high thermal conductivity, an additional layerover the gap with high thermal conductivity (such as ceramic or highthermal conductivity plastic or thermal grease, etc.) or other similarmethods can be used.

It will be apparent to the person knowledgeable in the art that severalgeneral embodiments are describe herein and the concepts can also beexpanded to include other similar geometries. The foregoing descriptionof the present invention has been provided for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise forms disclosed. The embodiments werechosen and described in order to best explain the principles of theinvention and its practical application, thereby enabling others skilledin the art to understand the invention for various embodiments and withvarious modifications that are suited to the particular usecontemplated. It is intended that the scope of the invention be definedby the following claims and their equivalence.

Some aspects of the present invention may be conveniently implementedusing a conventional general purpose or a specialized digital computer,microprocessor, or electronic circuitry programmed according to theteachings of the present disclosure. Appropriate software coding canreadily be prepared by skilled programmers and circuit designers basedon the teachings of the present disclosure, as will be apparent to thoseskilled in the art.

In some embodiments, the present invention includes a computer programproduct which is a storage medium (media) having instructions storedthereon/in which can be used to program a computer to perform any of theprocesses of the present invention. The storage medium can include, butis not limited to, any type of disk including floppy disks, opticaldiscs, DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs,EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or opticalcards, nanosystems (including molecular memory ICs), or any type ofmedia or device suitable for storing instructions and/or data.

The foregoing description of the present invention has been provided forthe purposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise forms disclosed.Many modifications and variations will be apparent to the practitionerskilled in the art. Particularly, while the embodiments of the systemsand methods described above are described in the context of chargingpads, it will be evident that the system and methods may be used withother types of chargers and/or power supplies. Similarly, while theembodiments described above are described in the context of chargingmobile devices, other types of devices can be used. The embodiments werechosen and described in order to best explain the principles of theinvention and its practical application, thereby enabling others skilledin the art to understand the invention for various embodiments and withvarious modifications that are suited to the particular usecontemplated. It is intended that the scope of the invention be definedby the following claims and their equivalence.

What is claimed is:
 1. A system for inductive charging including use ofafter-market accessories, comprising: a receiver coil or receiverassociated with a mobile device, and provided as a separable orafter-market accessory for use with the mobile device; and wherein, whenthe mobile device is placed in proximity to a base unit having one ormore charger coils, the charger coil is used to inductively generate acurrent in the receiver coil or receiver associated with the mobiledevice, to charge or power the mobile device.
 2. The system of claim 1,wherein the receiver coil or receiver is a component of, or is attachedto a shell, case, or other cover of the mobile device, provided as anafter-market accessory that replaces an original shell, case, or coverof the mobile device.
 3. The system of claim 1, wherein the receivercoil or receiver is connected to a power input jack of the mobile deviceand/or to battery connectors within the mobile device.
 4. The system ofclaim 1, wherein the base unit and mobile device communicate with eachother prior to and/or during charging or powering to verify theauthenticity, power requirements and/or other characteristics of themobile device or a battery therein and/or verify or handshake thepresence of the mobile device proximate the base unit.
 5. The system ofclaim 1, wherein the receiver coil or receiver is integrated into amobile device case or battery door which includes a mobile deviceconnector that mates with a corresponding power connector of the mobiledevice, to provide power and/or data to the mobile device.
 6. The systemof claim 1, wherein the receiver coil or receiver is integrated into amobile device case or battery door which connect with a power input jackof the mobile device and include a pass-through that allows forconnection of a wired power and/or data cable.
 7. The system of claim 1,wherein the receiver coil or receiver is incorporated into arechargeable battery for use with the mobile device.
 8. The system ofclaim 1, wherein the base unit is integrated within an automobile. 9.The system of claim 1, wherein the base unit is integrated within anautomobile, and wherein the base unit includes one or more componentsfor providing context-aware connectivity and/or other capabilities witha mobile device including, upon charging or powering the mobile device,configuring various aspects of the automobile environment.
 10. Thesystem of claim 1, wherein the mobile device is an automobile.
 11. Amethod of inductive charging including use of after-market accessories,comprising the steps of: providing a receiver coil or receiverassociated with a mobile device, and provided as a separable orafter-market accessory for use with the mobile device; and wherein, whenthe mobile device is placed in proximity to a base unit having one ormore charger coils, the charger coil is used to inductively generate acurrent in the receiver coil or receiver associated with the mobiledevice, to charge or power the mobile device.
 12. The method of claim11, wherein the receiver coil or receiver is a component of, or isattached to a shell, case, or other cover of the mobile device, providedas an after-market accessory that replaces an original shell, case, orcover of the mobile device.
 13. The method of claim 11, wherein thereceiver coil or receiver is connected to a power input jack of themobile device and/or to battery connectors within the mobile device. 14.The method of claim 11, wherein the base unit and mobile devicecommunicate with each other prior to and/or during charging or poweringto verify the authenticity, power requirements and/or othercharacteristics of the mobile device or a battery therein and/or verifyor handshake the presence of the mobile device proximate the base unit.15. The method of claim 11, wherein the receiver coil or receiver isintegrated into a mobile device case or battery door which includes amobile device connector that mates with a corresponding power connectorof the mobile device, to provide power and/or data to the mobile device.16. The method of claim 11, wherein the receiver coil or receiver isintegrated into a mobile device case or battery door which connect witha power input jack of the mobile device and include a pass-through thatallows for connection of a wired power and/or data cable.
 17. The methodof claim 11, wherein the receiver coil or receiver is incorporated intoa rechargeable battery for use with the mobile device.
 18. The method ofclaim 11, wherein the base unit is integrated within an automobile. 19.The method of claim 11, wherein the base unit is integrated within anautomobile, and wherein the base unit includes one or more componentsfor providing context-aware connectivity and/or other capabilities witha mobile device including, upon charging or powering the mobile device,configuring various aspects of the automobile environment.
 20. Themethod of claim 11, wherein the mobile device is an automobile.